diff --git a/src/eval.cpp b/src/eval.cpp
index ff0c35b..3120d35 100644
--- a/src/eval.cpp
+++ b/src/eval.cpp
@@ -1,5 +1,3 @@
-Source_Code_Location* current_source_code_location = nullptr;
-
 proc apply_arguments_to_function(Lisp_Object* arguments, Function* function) -> Lisp_Object* {
     Environment* new_env = Memory::create_child_environment(function->parent_environment);
 
@@ -389,7 +387,7 @@ proc eval_expr(Lisp_Object* node, Environment* env) -> Lisp_Object* {
         return symbol;
     }
     case Lisp_Object_Type::Pair: {
-        current_source_code_location = node->sourceCodeLocation;
+        current_source_code = node;
 
         Lisp_Object* lispOperator;
         if (node->value.pair.first->type != Lisp_Object_Type::CFunction &&
@@ -429,7 +427,7 @@ proc eval_expr(Lisp_Object* node, Environment* env) -> Lisp_Object* {
         }
     }
     default: {
-        create_generic_error("Not a function.");
+        create_generic_error("%s is not a function.", Lisp_Object_Type_to_string(node->type));
         return nullptr;
     }
     }
diff --git a/src/forward_decls.cpp b/src/forward_decls.cpp
index 0a282f8..1b39434 100644
--- a/src/forward_decls.cpp
+++ b/src/forward_decls.cpp
@@ -15,3 +15,5 @@ proc Lisp_Object_Type_to_string(Lisp_Object_Type type) -> const char*;
 namespace Memory {
     proc get_or_create_lisp_object_keyword(const char* identifier) -> Lisp_Object*;
 }
+
+Lisp_Object* current_source_code = nullptr;
diff --git a/src/io.cpp b/src/io.cpp
index e20f154..d76ed4a 100644
--- a/src/io.cpp
+++ b/src/io.cpp
@@ -281,14 +281,16 @@ proc print(Lisp_Object* node, bool print_quotes = false, FILE* file = stdout) ->
 
 
 proc print_error_location() -> void {
-    // if (error->location) {
-    //     printf("%s (line %d, position %d)",
-    //            Memory::get_c_str(error->location->file),
-    //            error->location->line,
-    //            error->location->column);
-    // } else {
-    //     printf("no source code location avaliable");
-    // }
+    if (current_source_code) {
+        printf("%s (line %d, position %d) code:" console_red "\n    ",
+               Memory::get_c_str(
+                   current_source_code->sourceCodeLocation->file),
+               current_source_code->sourceCodeLocation->line,
+               current_source_code->sourceCodeLocation->column);
+        print(current_source_code);
+    } else {
+        printf("no source code location avaliable");
+    }
 }
 
 proc log_error() -> void {
diff --git a/src/memory.cpp b/src/memory.cpp
index 3ab5694..3f85ebc 100644
--- a/src/memory.cpp
+++ b/src/memory.cpp
@@ -143,7 +143,7 @@ namespace Memory {
         t->type = Lisp_Object_Type::T;
     }
 
-    proc reset() {
+    proc reset() -> void {
         free_spots_in_object_memory->next_index = 0;
         free_spots_in_string_memory->next_index = 0;
         next_index_in_object_memory = 2; // because t and nil are always there
diff --git a/src/slime.h b/src/slime.h
index edf6f4f..9e32f1a 100644
--- a/src/slime.h
+++ b/src/slime.h
@@ -13,17 +13,17 @@
 #undef _CRT_SECURE_NO_WARNINGS
 
 namespace Slime {
-#include "./defines.cpp"
-#include "./structs.cpp"
-#include "./forward_decls.cpp"
-#include "./memory.cpp"
-#include "./lisp_object.cpp"
-#include "./error.cpp"
-#include "./io.cpp"
-#include "./env.cpp"
-#include "./parse.cpp"
-#include "./eval.cpp"
-#include "./built_ins.cpp"
-#include "./testing.cpp"
-#include "./undefines.cpp"
+#    include "./defines.cpp"
+#    include "./structs.cpp"
+#    include "./forward_decls.cpp"
+#    include "./memory.cpp"
+#    include "./lisp_object.cpp"
+#    include "./error.cpp"
+#    include "./io.cpp"
+#    include "./env.cpp"
+#    include "./parse.cpp"
+#    include "./eval.cpp"
+#    include "./built_ins.cpp"
+#    include "./testing.cpp"
+#    include "./undefines.cpp"
 }
diff --git a/src/testing.cpp b/src/testing.cpp
index e173e38..8fccd81 100644
--- a/src/testing.cpp
+++ b/src/testing.cpp
@@ -480,7 +480,7 @@ proc test_singular_t_and_nil() -> testresult {
 
 proc test_file(const char* file) -> testresult {
     Memory::reset();
-    Environment* env = Memory::create_built_ins_environment();
+    static Environment* env = Memory::create_built_ins_environment();
 
     Parser::init(env);