diff --git a/src/common/executable.c b/src/common/executable.c
index f053cff..5c06200 100644
--- a/src/common/executable.c
+++ b/src/common/executable.c
@@ -82,6 +82,11 @@ static const InstrInfo instr_table[] = {
 	[OPCODE_JUMP] = {"JUMP", 1, (OperandType[]) {OPTP_INT}},
 };
 
+const char *Executable_GetOpcodeName(Opcode opcode)
+{
+	return instr_table[opcode].name;
+}
+
 Executable *Executable_Copy(Executable *exe)
 {
 	assert(exe != NULL);
diff --git a/src/common/executable.h b/src/common/executable.h
index 82c5ff5..320f7ad 100644
--- a/src/common/executable.h
+++ b/src/common/executable.h
@@ -70,6 +70,7 @@ _Bool 		Executable_SetSource(Executable *exe, Source *src);
 Source 	   *Executable_GetSource(Executable *exe);
 int 		Executable_GetInstrOffset(Executable *exe, int index);
 int 		Executable_GetInstrLength(Executable *exe, int index);
+const char *Executable_GetOpcodeName(Opcode opcode);
 
 ExeBuilder *ExeBuilder_New(BPAlloc *alloc);
 _Bool 		ExeBuilder_Append(ExeBuilder *exeb, Error *error, Opcode opcode, Operand *opv, int opc, int off, int len);
diff --git a/src/runtime/runtime.c b/src/runtime/runtime.c
index a2bd540..e3ca8d3 100644
--- a/src/runtime/runtime.c
+++ b/src/runtime/runtime.c
@@ -530,7 +530,7 @@ static Object *do_relational_op(Object *lop, Object *rop, Opcode opcode, Heap *h
 static _Bool step(Runtime *runtime, Error *error)
 {
 	assert(runtime != NULL);
-	assert(error->occurred != 0);
+	assert(error->occurred == 0);
 	Opcode opcode;	
 	Operand ops[3];
 	int     opc = sizeof(ops) / sizeof(ops[0]);
@@ -815,18 +815,29 @@ static _Bool step(Runtime *runtime, Error *error)
 				if(!Runtime_Pop(runtime, error, 2))
 					return 0;
 
-				Object *val = Object_Select(col, key, runtime->heap, error);
+				assert(error->occurred == 0);
+
+				Error dummy;
+				Error_Init(&dummy); // We want to catch the error reported by this Object_Select.
+
+				Object *val = Object_Select(col, key, runtime->heap, &dummy);
 
 				if(val == NULL)
 					{
+						Error_Free(&dummy);
+
 						val = Object_NewNone(runtime->heap, error);
 
 						if(val == NULL)
 							return 0;
 					}
 
+				assert(error->occurred == 0);
+
 				if(!Runtime_Push(runtime, error, val))
 					return 0;
+
+				assert(error->occurred == 0);
 				return 1;
 			}