diff --git a/src/common/fontcmn.cpp b/src/common/fontcmn.cpp
index f5c47bd001..74f105e2a2 100644
--- a/src/common/fontcmn.cpp
+++ b/src/common/fontcmn.cpp
@@ -812,9 +812,9 @@ wxString wxNativeFontInfo::ToString() const
 {
     wxString s;
 
-    s.Printf(wxT("%d;%f;%d;%d;%d;%d;%d;%s;%d"),
+    s.Printf(wxT("%d;%s;%d;%d;%d;%d;%d;%s;%d"),
              1,                                 // version
-             GetFractionalPointSize(),
+             wxString::FromCDouble(GetFractionalPointSize()),
              family,
              (int)style,
              weight,
diff --git a/src/msw/font.cpp b/src/msw/font.cpp
index 76a2cc3c35..ed9840e0e6 100644
--- a/src/msw/font.cpp
+++ b/src/msw/font.cpp
@@ -739,9 +739,9 @@ wxString wxNativeFontInfo::ToString() const
 {
     wxString s;
 
-    s.Printf(wxS("%d;%f;%ld;%ld;%ld;%ld;%ld;%d;%d;%d;%d;%d;%d;%d;%d;%s"),
+    s.Printf(wxS("%d;%s;%ld;%ld;%ld;%ld;%ld;%d;%d;%d;%d;%d;%d;%d;%d;%s"),
              1, // version
-             pointSize,
+             wxString::FromCDouble(pointSize),
              lf.lfHeight,
              lf.lfWidth,
              lf.lfEscapement,
diff --git a/src/osx/carbon/font.cpp b/src/osx/carbon/font.cpp
index 53775b16b3..73f22a35fb 100644
--- a/src/osx/carbon/font.cpp
+++ b/src/osx/carbon/font.cpp
@@ -971,9 +971,9 @@ wxString wxNativeFontInfo::ToString() const
 {
     wxString s;
 
-    s.Printf(wxT("%d;%f;%d;%d;%d;%d;%d;%s;%d"),
+    s.Printf(wxT("%d;%s;%d;%d;%d;%d;%d;%s;%d"),
         1, // version
-        GetFractionalPointSize(),
+        wxString::FromCDouble(GetFractionalPointSize()),
         GetFamily(),
         (int)GetStyle(),
         GetNumericWeight(),