diff --git a/src/librustc_codegen_llvm/callee.rs b/src/librustc_codegen_llvm/callee.rs
index 43a5767e5c6..2d732adcb91 100644
--- a/src/librustc_codegen_llvm/callee.rs
+++ b/src/librustc_codegen_llvm/callee.rs
@@ -113,7 +113,7 @@ pub fn get_fn(
         unsafe {
             llvm::LLVMRustSetLinkage(llfn, llvm::Linkage::ExternalLinkage);
 
-            let is_generic = instance.substs.types().next().is_some();
+            let is_generic = instance.substs.non_erasable_generics().next().is_some();
 
             if is_generic {
                 // This is a monomorphization. Its expected visibility depends
diff --git a/src/librustc_codegen_ssa/back/symbol_export.rs b/src/librustc_codegen_ssa/back/symbol_export.rs
index 7da28c19d24..336f41b784a 100644
--- a/src/librustc_codegen_ssa/back/symbol_export.rs
+++ b/src/librustc_codegen_ssa/back/symbol_export.rs
@@ -263,7 +263,7 @@ fn exported_symbols_provider_local<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
                 def: InstanceDef::Item(def_id),
                 substs,
             }) = mono_item {
-                if substs.types().next().is_some() {
+                if substs.non_erasable_generics().next().is_some() {
                     symbols.push((ExportedSymbol::Generic(def_id, substs),
                                   SymbolExportLevel::Rust));
                 }
diff --git a/src/librustc_codegen_ssa/mir/operand.rs b/src/librustc_codegen_ssa/mir/operand.rs
index 0a6549851f4..55a1eb016e0 100644
--- a/src/librustc_codegen_ssa/mir/operand.rs
+++ b/src/librustc_codegen_ssa/mir/operand.rs
@@ -76,6 +76,8 @@ impl<'a, 'tcx: 'a, V: CodegenObject> OperandRef<'tcx, V> {
         }
 
         let val = match val.val {
+            ConstValue::Param(_) => bug!("encountered a ConstValue::Param in codegen"),
+            ConstValue::Infer(_) => bug!("encountered a ConstValue::Infer in codegen"),
             ConstValue::Scalar(x) => {
                 let scalar = match layout.abi {
                     layout::Abi::Scalar(ref x) => x,
diff --git a/src/librustc_codegen_utils/symbol_names.rs b/src/librustc_codegen_utils/symbol_names.rs
index f529cf30a62..76e74e9e2b4 100644
--- a/src/librustc_codegen_utils/symbol_names.rs
+++ b/src/librustc_codegen_utils/symbol_names.rs
@@ -172,7 +172,7 @@ fn get_symbol_hash<'a, 'tcx>(
         assert!(!substs.needs_subst());
         substs.hash_stable(&mut hcx, &mut hasher);
 
-        let is_generic = substs.types().next().is_some();
+        let is_generic = substs.non_erasable_generics().next().is_some();
         let avoid_cross_crate_conflicts =
             // If this is an instance of a generic function, we also hash in
             // the ID of the instantiating crate. This avoids symbol conflicts