diff --git a/engine/compiler.c b/engine/compiler.c
index 0f270c3..ff48381 100644
--- a/engine/compiler.c
+++ b/engine/compiler.c
@@ -2466,6 +2466,8 @@ static sxi32 PH7_CompileVar(ph7_gen_state *pGen) {
 				PH7_VmEmitInstr(pGen->pVm, pGen->pIn->nLine, PH7_OP_DONE, (rc != SXERR_EMPTY ? 1 : 0), 1, 0, 0);
 				/* Restore default bytecode container */
 				PH7_VmSetByteCodeContainer(pGen->pVm, pInstrContainer);
+			} else if(nType == MEMOBJ_NULL) {
+				PH7_GenCompileError(&(*pGen), E_ERROR, pGen->pIn->nLine, "Implicitly-typed variable '$%z' must be initialized", pName);
 			}
 			/* Set static variable type */
 			sStatic.iFlags = nType;
@@ -2492,6 +2494,8 @@ static sxi32 PH7_CompileVar(ph7_gen_state *pGen) {
 				} else {
 					PH7_VmEmitInstr(pGen->pVm, nLine, PH7_OP_POP, 1, 0, 0, 0);
 				}
+			} else if(nType == MEMOBJ_NULL) {
+				PH7_GenCompileError(&(*pGen), E_ERROR, pGen->pIn->nLine, "Implicitly-typed variable '$%z' must be initialized", pName);
 			} else {
 				pGen->pIn += 2; /* Jump the dollar '$' sign and variable name */
 			}
@@ -4926,7 +4930,7 @@ static ProcLangConstruct PH7_GenStateGetStatementHandler(
 	SyToken *pLookahead  /* Look-ahead token */
 ) {
 	sxu32 n = 0;
-	if((nKeywordID & PH7_KEYWORD_TYPEDEF) != 0 || nKeywordID == PH7_KEYWORD_STATIC) {
+	if((nKeywordID & PH7_KEYWORD_AUTO) != 0 || (nKeywordID & PH7_KEYWORD_TYPEDEF) != 0 || nKeywordID == PH7_KEYWORD_STATIC) {
 		if(nKeywordID == PH7_KEYWORD_STATIC && pLookahead && (pLookahead->nType & PH7_TK_OP)) {
 			const ph7_expr_op *pOp = (const ph7_expr_op *)pLookahead->pUserData;
 			if(pOp && pOp->iOp == EXPR_OP_DC /*::*/) {
diff --git a/engine/vm.c b/engine/vm.c
index f24c250..24af4f4 100644
--- a/engine/vm.c
+++ b/engine/vm.c
@@ -2421,20 +2421,22 @@ static sxi32 VmByteCodeExec(
 							PH7_VmThrowError(&(*pVm), PH7_CTX_ERR,
 											"Redeclaration of ‘$%z’ variable", &sName);
 						}
-						if(pInstr->iP2 & MEMOBJ_MIXED && (pInstr->iP2 & MEMOBJ_HASHMAP) == 0) {
-							pObj->nType = MEMOBJ_MIXED | MEMOBJ_VOID;
-						} else {
-							if(pInstr->iP2 & MEMOBJ_HASHMAP) {
-								ph7_hashmap *pMap;
-								pMap = PH7_NewHashmap(&(*pVm), 0, 0);
-								if(pMap == 0) {
-									PH7_VmMemoryError(&(*pVm));
+						if(pInstr->iP2 != MEMOBJ_NULL) {
+							if(pInstr->iP2 & MEMOBJ_MIXED && (pInstr->iP2 & MEMOBJ_HASHMAP) == 0) {
+								pObj->nType = MEMOBJ_MIXED | MEMOBJ_VOID;
+							} else {
+								if(pInstr->iP2 & MEMOBJ_HASHMAP) {
+									ph7_hashmap *pMap;
+									pMap = PH7_NewHashmap(&(*pVm), 0, 0);
+									if(pMap == 0) {
+										PH7_VmMemoryError(&(*pVm));
+									}
+									pObj->x.pOther = pMap;
 								}
-								pObj->x.pOther = pMap;
+								MemObjSetType(pObj, pInstr->iP2);
 							}
-							MemObjSetType(pObj, pInstr->iP2);
+							pTos->nIdx = SXU32_HIGH; /* Mark as constant */
 						}
-						pTos->nIdx = SXU32_HIGH; /* Mark as constant */
 					}
 					break;
 				}