diff --git a/imgui.cpp b/imgui.cpp
index 92e84da09c41..162d552722e5 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -1258,8 +1258,7 @@ ImGuiIO::ImGuiIO()
 // - on Windows you can get those using ToAscii+keyboard state, or via the WM_CHAR message
 void ImGuiIO::AddInputCharacter(unsigned int c)
 {
-    if (c > 0 && c < (sizeof(ImWchar) == 2 ? 0x10000 : 0x110000))
-        InputQueueCharacters.push_back((ImWchar)c);
+    InputQueueCharacters.push_back(c > 0 && c < IM_UNICODE_MAX_CODEPOINT ? (ImWchar)c : 0xFFFD);
 }
 
 // UTF16 strings use surrogate pairs to encode codepoints >= 0x10000, so
@@ -1268,22 +1267,22 @@ void ImGuiIO::AddInputCharacterUTF16(ImWchar16 c)
 {
     if ((c & 0xFC00) == 0xD800) // High surrogate, must save
     {
-        if (Surrogate != 0)
+        if (InputQueueSurrogate != 0)
             InputQueueCharacters.push_back(0xFFFD);
-        Surrogate = c;
+        InputQueueSurrogate = c;
         return;
     }
 
     ImWchar cp = c;
-    if (Surrogate != 0)
+    if (InputQueueSurrogate != 0)
     {
         if ((c & 0xFC00) != 0xDC00) // Invalid low surrogate
             InputQueueCharacters.push_back(0xFFFD);
-        else if (sizeof(ImWchar) == 2)
+        else if (IM_UNICODE_MAX_CODEPOINT == 0x10000) // Codepoint will not fit in ImWchar
             cp = 0xFFFD;
         else
-            cp = ((ImWchar)(Surrogate - 0xD800) << 10) + (c - 0xDC00) + 0x10000;
-        Surrogate = 0;
+            cp = (ImWchar)(((InputQueueSurrogate - 0xD800) << 10) + (c - 0xDC00) + 0x10000);
+        InputQueueSurrogate = 0;
     }
     InputQueueCharacters.push_back(cp);
 }
@@ -1713,8 +1712,8 @@ int ImTextCharFromUtf8(unsigned int* out_char, const char* in_text, const char*
         c += (*str++ & 0x3f);
         // utf-8 encodings of values used in surrogate pairs are invalid
         if ((c & 0xFFFFF800) == 0xD800) return 4;
-        // If ImWchar is 16bit, use replacement character U+FFFD instead
-        if (sizeof(ImWchar) == 2 && c >= 0x10000) c = 0xFFFD;
+        // If codepoint does not fit in ImWchar, use replacement character U+FFFD instead
+        if (c >= IM_UNICODE_MAX_CODEPOINT) c = 0xFFFD;
         *out_char = c;
         return 4;
     }
diff --git a/imgui.h b/imgui.h
index c2156cad00bc..3bb89b48b9e9 100644
--- a/imgui.h
+++ b/imgui.h
@@ -160,6 +160,8 @@ typedef int ImGuiWindowFlags;       // -> enum ImGuiWindowFlags_     // Flags: f
 typedef int (*ImGuiInputTextCallback)(ImGuiInputTextCallbackData *data);
 typedef void (*ImGuiSizeCallback)(ImGuiSizeCallbackData* data);
 
+#define IM_UNICODE_MAX_CODEPOINT (sizeof(ImWchar) == 2 ? 0x10000 : 0x110000)
+
 // Scalar data types
 typedef signed char         ImS8;   // 8-bit signed integer == char
 typedef unsigned char       ImU8;   // 8-bit unsigned integer
@@ -1466,7 +1468,7 @@ struct ImGuiIO
     float       KeysDownDurationPrev[512];      // Previous duration the key has been down
     float       NavInputsDownDuration[ImGuiNavInput_COUNT];
     float       NavInputsDownDurationPrev[ImGuiNavInput_COUNT];
-    ImWchar16   Surrogate;                      // For AddInputCharacterUTF16
+    ImWchar16   InputQueueSurrogate;            // For AddInputCharacterUTF16
     ImVector<ImWchar> InputQueueCharacters;     // Queue of _characters_ input (obtained by platform back-end). Fill using AddInputCharacter() helper.
 
     IMGUI_API   ImGuiIO();
@@ -2047,7 +2049,7 @@ struct ImFontGlyphRangesBuilder
     ImVector<ImU32> UsedChars;            // Store 1-bit per Unicode code point (0=unused, 1=used)
 
     ImFontGlyphRangesBuilder()          { Clear(); }
-    inline void     Clear()             { int size_in_bytes = (sizeof(ImWchar) == 2 ? 0x10000 : 0x110000) / 8; UsedChars.resize(size_in_bytes / (int)sizeof(ImU32)); memset(UsedChars.Data, 0, (size_t)size_in_bytes); }
+    inline void     Clear()             { int size_in_bytes = IM_UNICODE_MAX_CODEPOINT / 8; UsedChars.resize(size_in_bytes / (int)sizeof(ImU32)); memset(UsedChars.Data, 0, (size_t)size_in_bytes); }
     inline bool     GetBit(int n) const { int off = (n >> 5); ImU32 mask = 1u << (n & 31); return (UsedChars[off] & mask) != 0; }  // Get bit n in the array
     inline void     SetBit(int n)       { int off = (n >> 5); ImU32 mask = 1u << (n & 31); UsedChars[off] |= mask; }               // Set bit n in the array
     inline void     AddChar(ImWchar c)  { SetBit(c); }                          // Add character