diff --git a/include/wx/font.h b/include/wx/font.h
index 4dc01f55e1..76eb570015 100644
--- a/include/wx/font.h
+++ b/include/wx/font.h
@@ -19,6 +19,7 @@
 #include "wx/fontenc.h"     // the font encoding constants
 #include "wx/gdiobj.h"      // the base class
 #include "wx/gdicmn.h"      // for wxGDIObjListBase
+#include "wx/math.h"        // for wxRound()
 
 // ----------------------------------------------------------------------------
 // forward declarations
@@ -216,6 +217,25 @@ public:
 
     // Default copy ctor, assignment operator and dtor are OK.
 
+
+    // Helper functions for converting between integer and fractional sizes.
+    static int ToIntPointSize(float pointSize) { return wxRound(pointSize); }
+    static float ToFloatPointSize(int pointSize)
+    {
+        wxCHECK_MSG( pointSize == -1 || pointSize >= 0,
+                     -1, "Invalid font point size" );
+
+        // Huge values are not exactly representable as floats, so don't accept
+        // those neither as they can only be due to a mistake anyhow: nobody
+        // could possibly need a font of size 16777217pt (which is the first
+        // value for which this fails).
+        const float f = static_cast<float>(pointSize);
+        wxCHECK_MSG( static_cast<int>(f) == pointSize,
+                     -1, "Font point size out of range" );
+
+        return f;
+    }
+
 private:
     void Init()
     {
diff --git a/src/common/fontcmn.cpp b/src/common/fontcmn.cpp
index 66451ced9d..998c3c1caa 100644
--- a/src/common/fontcmn.cpp
+++ b/src/common/fontcmn.cpp
@@ -28,7 +28,6 @@
 #ifndef WX_PRECOMP
     #include "wx/dc.h"
     #include "wx/intl.h"
-    #include "wx/math.h"
     #include "wx/dcscreen.h"
     #include "wx/log.h"
     #include "wx/gdicmn.h"
@@ -45,8 +44,6 @@
 
 #include "wx/tokenzr.h"
 
-#include <float.h>      // for FLT_MAX
-
 // debugger helper: this function can be called from a debugger to show what
 // the date really is
 extern const char *wxDumpFont(const wxFont *font)
@@ -283,7 +280,7 @@ wxFontWeight wxFontBase::GetWeightClosestToNumericValue(int numWeight)
 
 int wxFontBase::GetPointSize() const
 {
-    return wxRound(GetFractionalPointSize());
+    return wxFontInfo::ToIntPointSize(GetFractionalPointSize());
 }
 
 
@@ -308,10 +305,7 @@ bool wxFontBase::IsUsingSizeInPixels() const
 
 void wxFontBase::SetPointSize(int pointSize)
 {
-    wxCHECK_RET( pointSize >= 0 && static_cast<float>(pointSize) < FLT_MAX,
-                 "Invalid font point size" );
-
-    SetFractionalPointSize(static_cast<float>(pointSize));
+    SetFractionalPointSize(wxFontInfo::ToFloatPointSize(pointSize));
 }
 
 void wxFontBase::SetPixelSize( const wxSize& pixelSize )
@@ -710,12 +704,12 @@ void wxNativeFontInfo::SetFaceName(const wxArrayString& facenames)
 
 int wxNativeFontInfo::GetPointSize() const
 {
-    return wxRound(GetFractionalPointSize());
+    return wxFontInfo::ToIntPointSize(GetFractionalPointSize());
 }
 
 void wxNativeFontInfo::SetPointSize(int pointsize)
 {
-    SetFractionalPointSize(static_cast<float>(pointsize));
+    SetFractionalPointSize(wxFontInfo::ToFloatPointSize(pointsize));
 }
 
 #ifdef wxNO_NATIVE_FONTINFO
diff --git a/src/osx/carbon/font.cpp b/src/osx/carbon/font.cpp
index abf4df5248..d2e1967eaa 100644
--- a/src/osx/carbon/font.cpp
+++ b/src/osx/carbon/font.cpp
@@ -578,7 +578,8 @@ bool wxFont::Create(int pointSize,
 {
     AccountForCompatValues(pointSize, style, weight);
 
-    return Create((float)pointSize, family, style, weight, underlined, faceName, encoding);
+    return Create(wxFontInfo::ToFloatPointSize(pointSize),
+                  family, style, weight, underlined, faceName, encoding);
 }
 
 wxFont::~wxFont()