diff --git a/src/emu/devfind.h b/src/emu/devfind.h
index 2493a66782f..e268bc9784a 100644
--- a/src/emu/devfind.h
+++ b/src/emu/devfind.h
@@ -267,8 +267,10 @@ public:
 	// construction/destruction
 	ioport_array_finder(device_t &base, const char *basetag)
 	{
-		for (int index = 0; index < _Count; index++) {
-			m_array[index].reset(global_alloc(ioport_finder_type(base, strformat(m_tag[index], "%s.%d", basetag, index).c_str())));
+		for (int index = 0; index < _Count; index++)
+		{
+			strformat(m_tag[index], "%s.%d", basetag, index);
+			m_array[index].reset(global_alloc(ioport_finder_type(base, m_tag[index].c_str())));
 		}
 	}
 
@@ -437,7 +439,10 @@ public:
 	shared_ptr_array_finder(device_t &base, const char *basetag, UINT8 width = sizeof(_PointerType) * 8)
 	{
 		for (int index = 0; index < _Count; index++)
-			m_array[index].reset(global_alloc(shared_ptr_type(base, strformat(m_tag[index],"%s.%d", basetag, index).c_str(), width)));
+		{
+			strformat(m_tag[index],"%s.%d", basetag, index);
+			m_array[index].reset(global_alloc(shared_ptr_type(base, m_tag[index].c_str(), width)));
+		}
 	}
 
 	// array accessors