diff --git a/Compiler/Builtin.mo b/Compiler/Builtin.mo
index 77ae654ebd2..eb7ce563b61 100644
--- a/Compiler/Builtin.mo
+++ b/Compiler/Builtin.mo
@@ -3482,8 +3482,6 @@ algorithm
       env = Env.extendFrameT(env, "sqrt", sqrtreal2real);
       env = Env.extendFrameT(env, "mod", realReal2real);
       env = Env.extendFrameT(env, "mod", intInt2int);
-      env = Env.extendFrameT(env, "constrain", realrealreal2real);
-      env = Env.extendFrameT(env, "constrain", array1dimrealarray1dimrealarray1dimreal2array1dimreal);
       /*
       env = Env.extendFrameT(env, "semiLinear", realRealReal2real);
       env = Env.extendFrameT(env, "delay", realReal2real);
diff --git a/Compiler/Codegen.mo b/Compiler/Codegen.mo
index 22e3d4a58d5..dbe04ae1759 100644
--- a/Compiler/Codegen.mo
+++ b/Compiler/Codegen.mo
@@ -1282,7 +1282,7 @@ protected function isBuiltinFunction
   takes an Absyn.path and returns true if the name matches a modelica builtin function"
   input Absyn.Path path;
   output Boolean b;
-  list<String> builtins = { "delay","smooth","size","ndims","zeros","ones","fill","max","min","transpose","array","sum","product","pre","initial","terminal","floor","ceil","abs","sqrt","div","integer","mod","rem","diagonal","differentiate","simplify","noEvent","edge","sign","der","sample","change","cat","identity","vector","scalar","cross","String","skew","constrain" };
+  list<String> builtins = { "delay","smooth","size","ndims","zeros","ones","fill","max","min","transpose","array","sum","product","pre","initial","terminal","floor","ceil","abs","sqrt","div","integer","mod","rem","diagonal","differentiate","simplify","noEvent","edge","sign","der","sample","change","cat","identity","vector","scalar","cross","String","skew"};
 
 algorithm
   out := matchcontinue(path)