diff --git a/src/zig_llvm.cpp b/src/zig_llvm.cpp
index a74a683358..03a1475062 100644
--- a/src/zig_llvm.cpp
+++ b/src/zig_llvm.cpp
@@ -581,7 +581,7 @@ ZigLLVMDILocation *ZigLLVMGetDebugLoc(unsigned line, unsigned col, ZigLLVMDIScop
 void ZigLLVMSetFastMath(LLVMBuilderRef builder_wrapped, bool on_state) {
     if (on_state) {
         FastMathFlags fmf;
-        fmf.setUnsafeAlgebra();
+        fmf.setFast();
         unwrap(builder_wrapped)->setFastMathFlags(fmf);
     } else {
         unwrap(builder_wrapped)->clearFastMathFlags();