diff --git a/putty.h b/putty.h
index 57c23442..6132327f 100644
--- a/putty.h
+++ b/putty.h
@@ -2118,7 +2118,15 @@ bool conf_deserialise(Conf *conf, BinarySource *src);/*returns true on success*/
  * Functions to copy, free, serialise and deserialise FontSpecs.
  * Provided per-platform, to go with the platform's idea of a
  * FontSpec's contents.
+ *
+ * The full fontspec_new is declared in the platform header, because
+ * each platform may need it to have a different prototype, due to
+ * constructing fonts in different ways. But fontspec_new_default()
+ * will at least produce _some_ kind of a FontSpec, for use in
+ * situations where one needs to exist (e.g. to put in a Conf) and be
+ * freeable but won't actually be used for anything important.
  */
+FontSpec *fontspec_new_default(void);
 FontSpec *fontspec_copy(const FontSpec *f);
 void fontspec_free(FontSpec *f);
 void fontspec_serialise(BinarySink *bs, FontSpec *f);
diff --git a/test/fuzzterm.c b/test/fuzzterm.c
index 0d4597b1..ae838651 100644
--- a/test/fuzzterm.c
+++ b/test/fuzzterm.c
@@ -201,7 +201,7 @@ int platform_default_i(const char *name, int def)
 
 FontSpec *platform_default_fontspec(const char *name)
 {
-    return fontspec_new("");
+    return fontspec_new_default();
 }
 
 Filename *platform_default_filename(const char *name)
diff --git a/unix/pageant.c b/unix/pageant.c
index e813e934..c77abbac 100644
--- a/unix/pageant.c
+++ b/unix/pageant.c
@@ -172,7 +172,7 @@ void random_destroy_seed(void) {}
 char *platform_default_s(const char *name) { return NULL; }
 bool platform_default_b(const char *name, bool def) { return def; }
 int platform_default_i(const char *name, int def) { return def; }
-FontSpec *platform_default_fontspec(const char *name) { return fontspec_new(""); }
+FontSpec *platform_default_fontspec(const char *name) { return fontspec_new_default(); }
 Filename *platform_default_filename(const char *name) { return filename_from_str(""); }
 char *x_get_default(const char *key) { return NULL; }
 
diff --git a/unix/plink.c b/unix/plink.c
index 503ff8d7..76f4c936 100644
--- a/unix/plink.c
+++ b/unix/plink.c
@@ -64,7 +64,7 @@ int platform_default_i(const char *name, int def)
 
 FontSpec *platform_default_fontspec(const char *name)
 {
-    return fontspec_new("");
+    return fontspec_new_default();
 }
 
 Filename *platform_default_filename(const char *name)
diff --git a/unix/psusan.c b/unix/psusan.c
index 1d5816d5..f5f7ed2a 100644
--- a/unix/psusan.c
+++ b/unix/psusan.c
@@ -78,7 +78,7 @@ int platform_default_i(const char *name, int def)
 
 FontSpec *platform_default_fontspec(const char *name)
 {
-    return fontspec_new("");
+    return fontspec_new_default();
 }
 
 Filename *platform_default_filename(const char *name)
diff --git a/unix/sftp.c b/unix/sftp.c
index dafd4fd9..dd25fa20 100644
--- a/unix/sftp.c
+++ b/unix/sftp.c
@@ -52,7 +52,7 @@ int platform_default_i(const char *name, int def)
 
 FontSpec *platform_default_fontspec(const char *name)
 {
-    return fontspec_new("");
+    return fontspec_new_default();
 }
 
 Filename *platform_default_filename(const char *name)
diff --git a/unix/uppity.c b/unix/uppity.c
index 11fead95..36f2c99d 100644
--- a/unix/uppity.c
+++ b/unix/uppity.c
@@ -80,7 +80,7 @@ int platform_default_i(const char *name, int def)
 
 FontSpec *platform_default_fontspec(const char *name)
 {
-    return fontspec_new("");
+    return fontspec_new_default();
 }
 
 Filename *platform_default_filename(const char *name)
diff --git a/unix/utils/fontspec.c b/unix/utils/fontspec.c
index 7c5a0a2f..b9bf8195 100644
--- a/unix/utils/fontspec.c
+++ b/unix/utils/fontspec.c
@@ -13,6 +13,11 @@ FontSpec *fontspec_new(const char *name)
     return f;
 }
 
+FontSpec *fontspec_new_default(void)
+{
+    return fontspec_new("");
+}
+
 FontSpec *fontspec_copy(const FontSpec *f)
 {
     return fontspec_new(f->name);
diff --git a/unix/window.c b/unix/window.c
index c4bee7b7..103036b1 100644
--- a/unix/window.c
+++ b/unix/window.c
@@ -304,7 +304,7 @@ FontSpec *platform_default_fontspec(const char *name)
     if (!strcmp(name, "Font"))
         return fontspec_new(DEFAULT_GTK_FONT);
     else
-        return fontspec_new("");
+        return fontspec_new_default();
 }
 
 Filename *platform_default_filename(const char *name)
diff --git a/windows/controls.c b/windows/controls.c
index 8f14796e..1d1c74c0 100644
--- a/windows/controls.c
+++ b/windows/controls.c
@@ -1683,7 +1683,7 @@ void winctrl_layout(struct dlgparam *dp, struct winctrls *wc,
             shortcuts[nshortcuts++] = ctrl->fontselect.shortcut;
             statictext(&pos, escaped, 1, base_id);
             staticbtn(&pos, "", base_id+1, "Change...", base_id+2);
-            data = fontspec_new("", false, 0, 0);
+            data = fontspec_new_default();
             sfree(escaped);
             break;
           default:
diff --git a/windows/utils/defaults.c b/windows/utils/defaults.c
index 1a270009..928c02c4 100644
--- a/windows/utils/defaults.c
+++ b/windows/utils/defaults.c
@@ -11,7 +11,7 @@ FontSpec *platform_default_fontspec(const char *name)
     if (!strcmp(name, "Font"))
         return fontspec_new("Courier New", false, 10, ANSI_CHARSET);
     else
-        return fontspec_new("", false, 0, 0);
+        return fontspec_new_default();
 }
 
 Filename *platform_default_filename(const char *name)
diff --git a/windows/utils/fontspec.c b/windows/utils/fontspec.c
index 7e8d5175..7bdd3423 100644
--- a/windows/utils/fontspec.c
+++ b/windows/utils/fontspec.c
@@ -14,6 +14,11 @@ FontSpec *fontspec_new(const char *name, bool bold, int height, int charset)
     return f;
 }
 
+FontSpec *fontspec_new_default(void)
+{
+    return fontspec_new("", false, 0, 0);
+}
+
 FontSpec *fontspec_copy(const FontSpec *f)
 {
     return fontspec_new(f->name, f->isbold, f->height, f->charset);