diff --git a/src/Sema.zig b/src/Sema.zig
index bd7bdb48cb..09fd184320 100644
--- a/src/Sema.zig
+++ b/src/Sema.zig
@@ -291,8 +291,8 @@ pub const Block = struct {
                     try sema.errNote(ci.block, ci.src, parent, prefix ++ "it is inside a @cImport", .{});
                 },
                 .comptime_ret_ty => |rt| {
-                    const src_loc = if (try sema.funcDeclSrc(rt.func)) |capture| blk: {
-                        var src_loc = capture;
+                    const src_loc = if (try sema.funcDeclSrc(rt.func)) |fn_decl| blk: {
+                        var src_loc = fn_decl.srcLoc();
                         src_loc.lazy = .{ .node_offset_fn_type_ret_ty = 0 };
                         break :blk src_loc;
                     } else blk: {
@@ -5843,7 +5843,7 @@ fn lookupInNamespace(
     return null;
 }
 
-fn funcDeclSrc(sema: *Sema, func_inst: Air.Inst.Ref) !?Module.SrcLoc {
+fn funcDeclSrc(sema: *Sema, func_inst: Air.Inst.Ref) !?*Decl {
     const func_val = (try sema.resolveMaybeUndefVal(func_inst)) orelse return null;
     if (func_val.isUndef()) return null;
     const owner_decl_index = switch (func_val.tag()) {
@@ -5852,8 +5852,7 @@ fn funcDeclSrc(sema: *Sema, func_inst: Air.Inst.Ref) !?Module.SrcLoc {
         .decl_ref => sema.mod.declPtr(func_val.castTag(.decl_ref).?.data).val.castTag(.function).?.data.owner_decl,
         else => return null,
     };
-    const owner_decl = sema.mod.declPtr(owner_decl_index);
-    return owner_decl.srcLoc();
+    return sema.mod.declPtr(owner_decl_index);
 }
 
 pub fn analyzeSaveErrRetIndex(sema: *Sema, block: *Block) SemaError!Air.Inst.Ref {
@@ -6031,7 +6030,7 @@ fn zirCall(
             break :check_args;
         }
 
-        const decl_src = try sema.funcDeclSrc(func);
+        const maybe_decl = try sema.funcDeclSrc(func);
         const member_str = if (bound_arg_src != null) "member function " else "";
         const variadic_str = if (func_ty_info.is_var_args) "at least " else "";
         const msg = msg: {
@@ -6048,7 +6047,7 @@ fn zirCall(
             );
             errdefer msg.destroy(sema.gpa);
 
-            if (decl_src) |some| try sema.mod.errNoteNonLazy(some, msg, "function declared here", .{});
+            if (maybe_decl) |fn_decl| try sema.mod.errNoteNonLazy(fn_decl.srcLoc(), msg, "function declared here", .{});
             break :msg msg;
         };
         return sema.failWithOwnedErrorMsg(msg);
@@ -6242,7 +6241,7 @@ fn analyzeCall(
     const func_ty_info = func_ty.fnInfo();
     const cc = func_ty_info.cc;
     if (cc == .Naked) {
-        const decl_src = try sema.funcDeclSrc(func);
+        const maybe_decl = try sema.funcDeclSrc(func);
         const msg = msg: {
             const msg = try sema.errMsg(
                 block,
@@ -6252,7 +6251,7 @@ fn analyzeCall(
             );
             errdefer msg.destroy(sema.gpa);
 
-            if (decl_src) |some| try sema.mod.errNoteNonLazy(some, msg, "function declared here", .{});
+            if (maybe_decl) |fn_decl| try sema.mod.errNoteNonLazy(fn_decl.srcLoc(), msg, "function declared here", .{});
             break :msg msg;
         };
         return sema.failWithOwnedErrorMsg(msg);
@@ -6488,6 +6487,7 @@ fn analyzeCall(
                 &should_memoize,
                 memoized_call_key,
                 func_ty_info.param_types,
+                func,
             ) catch |err| switch (err) {
                 error.NeededSourceLocation => {
                     _ = sema.inst_map.remove(inst);
@@ -6504,6 +6504,7 @@ fn analyzeCall(
                         &should_memoize,
                         memoized_call_key,
                         func_ty_info.param_types,
+                        func,
                     );
                     return error.AnalysisFail;
                 },
@@ -6646,12 +6647,17 @@ fn analyzeCall(
         const args = try sema.arena.alloc(Air.Inst.Ref, uncasted_args.len);
         for (uncasted_args) |uncasted_arg, i| {
             if (i < fn_params_len) {
+                const opts: CoerceOpts = .{ .param_src = .{
+                    .func_inst = func,
+                    .param_i = @intCast(u32, i),
+                } };
                 const param_ty = func_ty.fnParamType(i);
                 args[i] = sema.analyzeCallArg(
                     block,
                     .unneeded,
                     param_ty,
                     uncasted_arg,
+                    opts,
                 ) catch |err| switch (err) {
                     error.NeededSourceLocation => {
                         const decl = sema.mod.declPtr(block.src_decl);
@@ -6660,6 +6666,7 @@ fn analyzeCall(
                             Module.argSrc(call_src.node_offset.x, sema.gpa, decl, i, bound_arg_src),
                             param_ty,
                             uncasted_arg,
+                            opts,
                         );
                         return error.AnalysisFail;
                     },
@@ -6741,6 +6748,7 @@ fn analyzeInlineCallArg(
     should_memoize: *bool,
     memoized_call_key: Module.MemoizedCall.Key,
     raw_param_types: []const Type,
+    func_inst: Air.Inst.Ref,
 ) !void {
     const zir_tags = sema.code.instructions.items(.tag);
     switch (zir_tags[inst]) {
@@ -6765,7 +6773,13 @@ fn analyzeInlineCallArg(
                     return err;
                 };
             }
-            const casted_arg = try sema.coerce(arg_block, param_ty, uncasted_arg, arg_src);
+            const casted_arg = sema.coerceExtra(arg_block, param_ty, uncasted_arg, arg_src, .{ .param_src = .{
+                .func_inst = func_inst,
+                .param_i = @intCast(u32, arg_i.*),
+            } }) catch |err| switch (err) {
+                error.NotCoercible => unreachable,
+                else => |e| return e,
+            };
 
             if (is_comptime_call) {
                 sema.inst_map.putAssumeCapacityNoClobber(inst, casted_arg);
@@ -6855,9 +6869,13 @@ fn analyzeCallArg(
     arg_src: LazySrcLoc,
     param_ty: Type,
     uncasted_arg: Air.Inst.Ref,
+    opts: CoerceOpts,
 ) !Air.Inst.Ref {
     try sema.resolveTypeFully(param_ty);
-    return sema.coerce(block, param_ty, uncasted_arg, arg_src);
+    return sema.coerceExtra(block, param_ty, uncasted_arg, arg_src, opts) catch |err| switch (err) {
+        error.NotCoercible => unreachable,
+        else => |e| return e,
+    };
 }
 
 fn analyzeGenericCallArg(
@@ -24056,6 +24074,25 @@ const CoerceOpts = struct {
     is_ret: bool = false,
     /// Should coercion to comptime_int ermit an error message.
     no_cast_to_comptime_int: bool = false,
+
+    param_src: struct {
+        func_inst: Air.Inst.Ref = .none,
+        param_i: u32 = undefined,
+
+        fn get(info: @This(), sema: *Sema) !?Module.SrcLoc {
+            if (info.func_inst == .none) return null;
+            const fn_decl = (try sema.funcDeclSrc(info.func_inst)) orelse return null;
+            const param_src = Module.paramSrc(0, sema.gpa, fn_decl, info.param_i);
+            if (param_src == .node_offset_param) {
+                return Module.SrcLoc{
+                    .file_scope = fn_decl.getFileScope(),
+                    .parent_decl_node = fn_decl.src_node,
+                    .lazy = LazySrcLoc.nodeOffset(param_src.node_offset_param),
+                };
+            }
+            return param_src.toSrcLoc(fn_decl);
+        }
+    } = .{},
 };
 
 fn coerceExtra(
@@ -24715,6 +24752,10 @@ fn coerceExtra(
             }
         }
 
+        if (try opts.param_src.get(sema)) |param_src| {
+            try sema.mod.errNoteNonLazy(param_src, msg, "parameter type declared here", .{});
+        }
+
         // TODO maybe add "cannot store an error in type '{}'" note
 
         break :msg msg;
diff --git a/test/cases/compile_errors/calling_var_args_extern_function_passing_array_instead_of_pointer.zig b/test/cases/compile_errors/calling_var_args_extern_function_passing_array_instead_of_pointer.zig
index 846a5ff81a..c9e2e2e5eb 100644
--- a/test/cases/compile_errors/calling_var_args_extern_function_passing_array_instead_of_pointer.zig
+++ b/test/cases/compile_errors/calling_var_args_extern_function_passing_array_instead_of_pointer.zig
@@ -8,3 +8,4 @@ pub extern fn foo(format: *const u8, ...) void;
 // target=native
 //
 // :2:16: error: expected type '*const u8', found '[5:0]u8'
+// :4:27: note: parameter type declared here
diff --git a/test/cases/compile_errors/casting_bit_offset_pointer_to_regular_pointer.zig b/test/cases/compile_errors/casting_bit_offset_pointer_to_regular_pointer.zig
index 132627557e..7fd38280c6 100644
--- a/test/cases/compile_errors/casting_bit_offset_pointer_to_regular_pointer.zig
+++ b/test/cases/compile_errors/casting_bit_offset_pointer_to_regular_pointer.zig
@@ -21,3 +21,4 @@ export fn entry() usize { return @sizeOf(@TypeOf(&foo)); }
 // :8:16: error: expected type '*const u3', found '*align(0:3:1) const u3'
 // :8:16: note: pointer host size '1' cannot cast into pointer host size '0'
 // :8:16: note: pointer bit offset '3' cannot cast into pointer bit offset '0'
+// :11:11: note: parameter type declared here
diff --git a/test/cases/compile_errors/closure_get_in_param_ty_instantiate_incorrectly.zig b/test/cases/compile_errors/closure_get_in_param_ty_instantiate_incorrectly.zig
index dc533442fb..8855755ec1 100644
--- a/test/cases/compile_errors/closure_get_in_param_ty_instantiate_incorrectly.zig
+++ b/test/cases/compile_errors/closure_get_in_param_ty_instantiate_incorrectly.zig
@@ -22,3 +22,4 @@ pub export fn entry() void {
 // target=native
 //
 // :17:25: error: expected type 'u32', found 'type'
+// :3:21: note: parameter type declared here
diff --git a/test/cases/compile_errors/disallow_coercion_from_non-null-terminated_pointer_to_null-terminated_pointer.zig b/test/cases/compile_errors/disallow_coercion_from_non-null-terminated_pointer_to_null-terminated_pointer.zig
index 0074c26de7..3670def4ee 100644
--- a/test/cases/compile_errors/disallow_coercion_from_non-null-terminated_pointer_to_null-terminated_pointer.zig
+++ b/test/cases/compile_errors/disallow_coercion_from_non-null-terminated_pointer_to_null-terminated_pointer.zig
@@ -11,3 +11,4 @@ pub export fn entry() void {
 //
 // :5:14: error: expected type '[*:0]const u8', found '[*]const u8'
 // :5:14: note: destination pointer requires '0' sentinel
+// :1:20: note: parameter type declared here
diff --git a/test/cases/compile_errors/double_pointer_to_anyopaque_pointer.zig b/test/cases/compile_errors/double_pointer_to_anyopaque_pointer.zig
index 6aa9618dbd..c7e54738d1 100644
--- a/test/cases/compile_errors/double_pointer_to_anyopaque_pointer.zig
+++ b/test/cases/compile_errors/double_pointer_to_anyopaque_pointer.zig
@@ -24,5 +24,6 @@ pub export fn entry3() void {
 // :4:35: note: cannot implicitly cast double pointer '*const *const usize' to anyopaque pointer '*const anyopaque'
 // :9:10: error: expected type '?*anyopaque', found '*[*:0]u8'
 // :9:10: note: cannot implicitly cast double pointer '*[*:0]u8' to anyopaque pointer '?*anyopaque'
+// :11:12: note: parameter type declared here
 // :15:35: error: expected type '*const anyopaque', found '*?*usize'
 // :15:35: note: cannot implicitly cast double pointer '*?*usize' to anyopaque pointer '*const anyopaque'
diff --git a/test/cases/compile_errors/implicitly_increasing_pointer_alignment.zig b/test/cases/compile_errors/implicitly_increasing_pointer_alignment.zig
index b9a9fb2faf..13adba1b91 100644
--- a/test/cases/compile_errors/implicitly_increasing_pointer_alignment.zig
+++ b/test/cases/compile_errors/implicitly_increasing_pointer_alignment.zig
@@ -18,3 +18,4 @@ fn bar(x: *u32) void {
 //
 // :8:9: error: expected type '*u32', found '*align(1) u32'
 // :8:9: note: pointer alignment '1' cannot cast into pointer alignment '4'
+// :11:11: note: parameter type declared here
diff --git a/test/cases/compile_errors/pass_const_ptr_to_mutable_ptr_fn.zig b/test/cases/compile_errors/pass_const_ptr_to_mutable_ptr_fn.zig
index 39c55870f1..fd24b58f55 100644
--- a/test/cases/compile_errors/pass_const_ptr_to_mutable_ptr_fn.zig
+++ b/test/cases/compile_errors/pass_const_ptr_to_mutable_ptr_fn.zig
@@ -16,3 +16,4 @@ export fn entry() usize { return @sizeOf(@TypeOf(&foo)); }
 //
 // :4:19: error: expected type '*[]const u8', found '*const []const u8'
 // :4:19: note: cast discards const qualifier
+// :6:14: note: parameter type declared here
diff --git a/test/cases/compile_errors/struct_init_passed_to_type_param.zig b/test/cases/compile_errors/struct_init_passed_to_type_param.zig
index b00c27986f..01906ac613 100644
--- a/test/cases/compile_errors/struct_init_passed_to_type_param.zig
+++ b/test/cases/compile_errors/struct_init_passed_to_type_param.zig
@@ -12,3 +12,4 @@ export const value = hi(MyStruct{ .x = 12 });
 //
 // :7:33: error: expected type 'type', found 'tmp.MyStruct'
 // :1:18: note: struct declared here
+// :3:19: note: parameter type declared here
diff --git a/test/cases/compile_errors/struct_type_mismatch_in_arg.zig b/test/cases/compile_errors/struct_type_mismatch_in_arg.zig
index 3e53189f2f..a52bdfab6c 100644
--- a/test/cases/compile_errors/struct_type_mismatch_in_arg.zig
+++ b/test/cases/compile_errors/struct_type_mismatch_in_arg.zig
@@ -15,3 +15,4 @@ comptime {
 // :7:16: error: expected type 'tmp.Foo', found 'tmp.Bar'
 // :1:13: note: struct declared here
 // :2:13: note: struct declared here
+// :4:18: note: parameter type declared here
diff --git a/test/cases/compile_errors/wrong_pointer_coerced_to_pointer_to_opaque_{}.zig b/test/cases/compile_errors/wrong_pointer_coerced_to_pointer_to_opaque_{}.zig
index e22c285cb0..a050eb6a4c 100644
--- a/test/cases/compile_errors/wrong_pointer_coerced_to_pointer_to_opaque_{}.zig
+++ b/test/cases/compile_errors/wrong_pointer_coerced_to_pointer_to_opaque_{}.zig
@@ -12,3 +12,4 @@ export fn foo() void {
 // :5:9: error: expected type '*tmp.Derp', found '*anyopaque'
 // :5:9: note: pointer type child 'anyopaque' cannot cast into pointer type child 'tmp.Derp'
 // :1:14: note: opaque declared here
+// :2:18: note: parameter type declared here