diff --git a/engine/compiler.c b/engine/compiler.c
index 1ef8b6e..6fd990b 100644
--- a/engine/compiler.c
+++ b/engine/compiler.c
@@ -3458,7 +3458,7 @@ static sxi32 PH7_GenStateCompileClassMethod(
 		/* Only method signature is allowed */
 		if(pGen->pIn < pGen->pEnd && (pGen->pIn->nType & PH7_TK_SEMI /* ';'*/) == 0) {
 			PH7_GenCompileError(pGen, E_ERROR, pGen->pIn->nLine,
-									 "Interface method '%z::%z()' cannot contain body", &pClass->sName, pName);
+									 "Interface or virtual method '%z::%z()' cannot contain body", &pClass->sName, pName);
 		}
 	}
 	/* Store method return data type */
diff --git a/engine/oop.c b/engine/oop.c
index 444d2f9..51a6645 100644
--- a/engine/oop.c
+++ b/engine/oop.c
@@ -282,7 +282,7 @@ PH7_PRIVATE sxi32 PH7_ClassInherit(ph7_vm *pVm, ph7_class *pSub, ph7_class *pBas
 		} else {
 			if(pMeth->iFlags & PH7_CLASS_ATTR_VIRTUAL) {
 				/* Virtual method must be defined in the child class */
-				PH7_VmThrowError(&(*pVm), PH7_CTX_ERR, "Virtual method '%z:%z()' must be defined inside child class '%z'", &pBase->sName, pName, &pSub->sName);
+				PH7_VmThrowError(&(*pVm), PH7_CTX_ERR, "Virtual method '%z::%z()' must be defined inside child class '%z'", &pBase->sName, pName, &pSub->sName);
 			}
 		}
 		/* Install the method */
diff --git a/engine/vm.c b/engine/vm.c
index 0bb1574..91439be 100644
--- a/engine/vm.c
+++ b/engine/vm.c
@@ -4331,7 +4331,7 @@ static sxi32 VmByteCodeExec(
 										}
 										PH7_MemObjRelease(pTos);
 									} else if((pMeth->iFlags & PH7_CLASS_ATTR_STATIC) == 0 && ((pClass->iFlags & PH7_CLASS_FINAL) == 0 || (pClass->iFlags & PH7_CLASS_VIRTUAL) == 0)) {
-										PH7_VmThrowError(&(*pVm), PH7_CTX_ERR, "Attempt to call statically a non-static method '%z::%z()'",
+										PH7_VmThrowError(&(*pVm), PH7_CTX_ERR, "An object reference is required for the non-static method '%z::%z()'",
 														&pClass->sName, &sName);
 									} else if(!VmClassMemberAccess(&(*pVm), pClass, pMeth->iProtection)) {
 										PH7_VmThrowError(&(*pVm), PH7_CTX_ERR, "Method '%z::%z()' is inaccessible due to its protection level",
@@ -4364,7 +4364,7 @@ static sxi32 VmByteCodeExec(
 									if(pAttr) {
 										if((pAttr->iFlags & (PH7_CLASS_ATTR_STATIC | PH7_CLASS_ATTR_CONSTANT)) == 0) {
 											/* Access to a non static attribute */
-											PH7_VmThrowError(&(*pVm), PH7_CTX_ERR, "Access to a non-static class attribute '%z::$%z'",
+											PH7_VmThrowError(&(*pVm), PH7_CTX_ERR, "An object reference is required for the non-static attribute '%z::$%z'",
 														  &pClass->sName, &pAttr->sName
 														 );
 										} else {