diff --git a/stage0/astgen.c b/stage0/astgen.c
index 80abb16522..019792336b 100644
--- a/stage0/astgen.c
+++ b/stage0/astgen.c
@@ -5443,6 +5443,24 @@ static uint32_t builtinCallMultiArg(GenZir* gz, Scope* scope, ResultLoc rl,
     }
     // clang-format on
 
+    // @mulAdd — AstGen.zig:9592-9603.
+    // clang-format off
+    if (name_len == 6 && memcmp(source + name_start, "mulAdd", 6) == 0
+        && param_count == 4) {
+        uint32_t float_type = typeExpr(gz, scope, params[0]);
+        ResultLoc coerced_rl = { .tag = RL_COERCED_TY,
+            .data = float_type, .src_node = 0, .ctx = RI_CTX_NONE };
+        uint32_t mulend1 = exprRl(gz, scope, coerced_rl, params[1]);
+        uint32_t mulend2 = exprRl(gz, scope, coerced_rl, params[2]);
+        ResultLoc ty_rl = { .tag = RL_TY,
+            .data = float_type, .src_node = 0, .ctx = RI_CTX_NONE };
+        uint32_t addend = exprRl(gz, scope, ty_rl, params[3]);
+        uint32_t result = addPlNodeTriple(
+            gz, ZIR_INST_MUL_ADD, node, mulend1, mulend2, addend);
+        return rvalue(gz, rl, result, node);
+    }
+    // clang-format on
+
     // @cmpxchgStrong / @cmpxchgWeak — AstGen.zig:9496-9497, 9884-9905.
     // clang-format off
     if (param_count == 6
diff --git a/stage0/astgen_test.zig b/stage0/astgen_test.zig
index 06bb5e7526..03e5be9211 100644
--- a/stage0/astgen_test.zig
+++ b/stage0/astgen_test.zig
@@ -1263,7 +1263,7 @@ const corpus_files = .{
     "../test/behavior/memmove.zig",
     "../test/behavior/memset.zig",
     "../test/behavior/merge_error_sets.zig",
-    //"../test/behavior/muladd.zig",
+    "../test/behavior/muladd.zig",
     //"../test/behavior/multiple_externs_with_conflicting_types.zig",
     "../test/behavior/namespace_depends_on_compile_var.zig",
     "../test/behavior/nan.zig",