diff --git a/src/gui/gui.cpp b/src/gui/gui.cpp
index 279e3242e..ed21ad994 100644
--- a/src/gui/gui.cpp
+++ b/src/gui/gui.cpp
@@ -5357,6 +5357,10 @@ bool FurnaceGUI::init() {
     logD("auto-detecting UI scale factor.");
     dpiScale=getScaleFactor(videoBackend);
     logD("scale factor: %f",dpiScale);
+    if (dpiScale<0.1f) {
+      logW("scale what?");
+      dpiScale=1.0f;
+    }
   }
 
 #if !(defined(__APPLE__) || defined(_WIN32))
diff --git a/src/gui/settings.cpp b/src/gui/settings.cpp
index 43adfc85a..50a36a9e8 100644
--- a/src/gui/settings.cpp
+++ b/src/gui/settings.cpp
@@ -3334,6 +3334,8 @@ void FurnaceGUI::applyUISettings(bool updateFonts) {
     ImGui::StyleColorsDark(&sty);
   }
 
+  if (dpiScale<0.1) dpiScale=0.1;
+
   setupLabel(settings.noteOffLabel.c_str(),noteOffLabel,3);
   setupLabel(settings.noteRelLabel.c_str(),noteRelLabel,3);
   setupLabel(settings.macroRelLabel.c_str(),macroRelLabel,3);
@@ -3539,21 +3541,21 @@ void FurnaceGUI::applyUISettings(bool updateFonts) {
     fc1.MergeMode=true;
 
     if (settings.mainFont==6) { // custom font
-      if ((mainFont=ImGui::GetIO().Fonts->AddFontFromFileTTF(settings.mainFontPath.c_str(),e->getConfInt("mainFontSize",18)*dpiScale,NULL,fontRange))==NULL) {
+      if ((mainFont=ImGui::GetIO().Fonts->AddFontFromFileTTF(settings.mainFontPath.c_str(),MAX(1,e->getConfInt("mainFontSize",18)*dpiScale),NULL,fontRange))==NULL) {
         logW("could not load UI font! reverting to default font");
         settings.mainFont=0;
-        if ((mainFont=ImGui::GetIO().Fonts->AddFontFromMemoryCompressedTTF(builtinFont[settings.mainFont],builtinFontLen[settings.mainFont],e->getConfInt("mainFontSize",18)*dpiScale,NULL,fontRange))==NULL) {
+        if ((mainFont=ImGui::GetIO().Fonts->AddFontFromMemoryCompressedTTF(builtinFont[settings.mainFont],builtinFontLen[settings.mainFont],MAX(1,e->getConfInt("mainFontSize",18)*dpiScale),NULL,fontRange))==NULL) {
           logE("could not load UI font! falling back to Proggy Clean.");
           mainFont=ImGui::GetIO().Fonts->AddFontDefault();
         }
       }
     } else if (settings.mainFont==5) { // system font
-      if ((mainFont=ImGui::GetIO().Fonts->AddFontFromFileTTF(SYSTEM_FONT_PATH_1,e->getConfInt("mainFontSize",18)*dpiScale,NULL,fontRange))==NULL) {
-        if ((mainFont=ImGui::GetIO().Fonts->AddFontFromFileTTF(SYSTEM_FONT_PATH_2,e->getConfInt("mainFontSize",18)*dpiScale,NULL,fontRange))==NULL) {
-          if ((mainFont=ImGui::GetIO().Fonts->AddFontFromFileTTF(SYSTEM_FONT_PATH_3,e->getConfInt("mainFontSize",18)*dpiScale,NULL,fontRange))==NULL) {
+      if ((mainFont=ImGui::GetIO().Fonts->AddFontFromFileTTF(SYSTEM_FONT_PATH_1,MAX(1,e->getConfInt("mainFontSize",18)*dpiScale),NULL,fontRange))==NULL) {
+        if ((mainFont=ImGui::GetIO().Fonts->AddFontFromFileTTF(SYSTEM_FONT_PATH_2,MAX(1,e->getConfInt("mainFontSize",18)*dpiScale),NULL,fontRange))==NULL) {
+          if ((mainFont=ImGui::GetIO().Fonts->AddFontFromFileTTF(SYSTEM_FONT_PATH_3,MAX(1,e->getConfInt("mainFontSize",18)*dpiScale),NULL,fontRange))==NULL) {
             logW("could not load UI font! reverting to default font");
             settings.mainFont=0;
-            if ((mainFont=ImGui::GetIO().Fonts->AddFontFromMemoryCompressedTTF(builtinFont[settings.mainFont],builtinFontLen[settings.mainFont],e->getConfInt("mainFontSize",18)*dpiScale,NULL,fontRange))==NULL) {
+            if ((mainFont=ImGui::GetIO().Fonts->AddFontFromMemoryCompressedTTF(builtinFont[settings.mainFont],builtinFontLen[settings.mainFont],MAX(1,e->getConfInt("mainFontSize",18)*dpiScale),NULL,fontRange))==NULL) {
               logE("could not load UI font! falling back to Proggy Clean.");
               mainFont=ImGui::GetIO().Fonts->AddFontDefault();
             }
@@ -3561,21 +3563,21 @@ void FurnaceGUI::applyUISettings(bool updateFonts) {
         }
       }
     } else {
-      if ((mainFont=ImGui::GetIO().Fonts->AddFontFromMemoryCompressedTTF(builtinFont[settings.mainFont],builtinFontLen[settings.mainFont],e->getConfInt("mainFontSize",18)*dpiScale,NULL,fontRange))==NULL) {
+      if ((mainFont=ImGui::GetIO().Fonts->AddFontFromMemoryCompressedTTF(builtinFont[settings.mainFont],builtinFontLen[settings.mainFont],MAX(1,e->getConfInt("mainFontSize",18)*dpiScale),NULL,fontRange))==NULL) {
         logE("could not load UI font! falling back to Proggy Clean.");
         mainFont=ImGui::GetIO().Fonts->AddFontDefault();
       }
     }
 
     // two fallback fonts
-    mainFont=ImGui::GetIO().Fonts->AddFontFromMemoryCompressedTTF(font_liberationSans_compressed_data,font_liberationSans_compressed_size,e->getConfInt("mainFontSize",18)*dpiScale,&fc1,fontRange);
-    mainFont=ImGui::GetIO().Fonts->AddFontFromMemoryCompressedTTF(font_unifont_compressed_data,font_unifont_compressed_size,e->getConfInt("mainFontSize",18)*dpiScale,&fc1,fontRange);
+    mainFont=ImGui::GetIO().Fonts->AddFontFromMemoryCompressedTTF(font_liberationSans_compressed_data,font_liberationSans_compressed_size,MAX(1,e->getConfInt("mainFontSize",18)*dpiScale),&fc1,fontRange);
+    mainFont=ImGui::GetIO().Fonts->AddFontFromMemoryCompressedTTF(font_unifont_compressed_data,font_unifont_compressed_size,MAX(1,e->getConfInt("mainFontSize",18)*dpiScale),&fc1,fontRange);
 
     ImFontConfig fc;
     fc.MergeMode=true;
     fc.GlyphMinAdvanceX=e->getConfInt("iconSize",16)*dpiScale;
     static const ImWchar fontRangeIcon[]={ICON_MIN_FA,ICON_MAX_FA,0};
-    if ((iconFont=ImGui::GetIO().Fonts->AddFontFromMemoryCompressedTTF(iconFont_compressed_data,iconFont_compressed_size,e->getConfInt("iconSize",16)*dpiScale,&fc,fontRangeIcon))==NULL) {
+    if ((iconFont=ImGui::GetIO().Fonts->AddFontFromMemoryCompressedTTF(iconFont_compressed_data,iconFont_compressed_size,MAX(1,e->getConfInt("iconSize",16)*dpiScale),&fc,fontRangeIcon))==NULL) {
       logE("could not load icon font!");
     }
 
@@ -3584,21 +3586,21 @@ void FurnaceGUI::applyUISettings(bool updateFonts) {
       patFont=mainFont;
     } else {
       if (settings.patFont==6) { // custom font
-        if ((patFont=ImGui::GetIO().Fonts->AddFontFromFileTTF(settings.patFontPath.c_str(),e->getConfInt("patFontSize",18)*dpiScale,NULL,upTo800))==NULL) {
+        if ((patFont=ImGui::GetIO().Fonts->AddFontFromFileTTF(settings.patFontPath.c_str(),MAX(1,e->getConfInt("patFontSize",18)*dpiScale),NULL,upTo800))==NULL) {
           logW("could not load pattern font! reverting to default font");
           settings.patFont=0;
-          if ((patFont=ImGui::GetIO().Fonts->AddFontFromMemoryCompressedTTF(builtinFontM[settings.patFont],builtinFontMLen[settings.patFont],e->getConfInt("patFontSize",18)*dpiScale,NULL,upTo800))==NULL) {
+          if ((patFont=ImGui::GetIO().Fonts->AddFontFromMemoryCompressedTTF(builtinFontM[settings.patFont],builtinFontMLen[settings.patFont],MAX(1,e->getConfInt("patFontSize",18)*dpiScale),NULL,upTo800))==NULL) {
             logE("could not load pattern font! falling back to Proggy Clean.");
             patFont=ImGui::GetIO().Fonts->AddFontDefault();
           }
         }
       } else if (settings.patFont==5) { // system font
-        if ((patFont=ImGui::GetIO().Fonts->AddFontFromFileTTF(SYSTEM_PAT_FONT_PATH_1,e->getConfInt("patFontSize",18)*dpiScale,NULL,upTo800))==NULL) {
-          if ((patFont=ImGui::GetIO().Fonts->AddFontFromFileTTF(SYSTEM_PAT_FONT_PATH_2,e->getConfInt("patFontSize",18)*dpiScale,NULL,upTo800))==NULL) {
-            if ((patFont=ImGui::GetIO().Fonts->AddFontFromFileTTF(SYSTEM_PAT_FONT_PATH_3,e->getConfInt("patFontSize",18)*dpiScale,NULL,upTo800))==NULL) {
+        if ((patFont=ImGui::GetIO().Fonts->AddFontFromFileTTF(SYSTEM_PAT_FONT_PATH_1,MAX(1,e->getConfInt("patFontSize",18)*dpiScale),NULL,upTo800))==NULL) {
+          if ((patFont=ImGui::GetIO().Fonts->AddFontFromFileTTF(SYSTEM_PAT_FONT_PATH_2,MAX(1,e->getConfInt("patFontSize",18)*dpiScale),NULL,upTo800))==NULL) {
+            if ((patFont=ImGui::GetIO().Fonts->AddFontFromFileTTF(SYSTEM_PAT_FONT_PATH_3,MAX(1,e->getConfInt("patFontSize",18)*dpiScale),NULL,upTo800))==NULL) {
               logW("could not load pattern font! reverting to default font");
               settings.patFont=0;
-              if ((patFont=ImGui::GetIO().Fonts->AddFontFromMemoryCompressedTTF(builtinFontM[settings.patFont],builtinFontMLen[settings.patFont],e->getConfInt("patFontSize",18)*dpiScale,NULL,upTo800))==NULL) {
+              if ((patFont=ImGui::GetIO().Fonts->AddFontFromMemoryCompressedTTF(builtinFontM[settings.patFont],builtinFontMLen[settings.patFont],MAX(1,e->getConfInt("patFontSize",18)*dpiScale),NULL,upTo800))==NULL) {
                 logE("could not load pattern font! falling back to Proggy Clean.");
                 patFont=ImGui::GetIO().Fonts->AddFontDefault();
               }
@@ -3606,7 +3608,7 @@ void FurnaceGUI::applyUISettings(bool updateFonts) {
           }
         }
       } else {
-        if ((patFont=ImGui::GetIO().Fonts->AddFontFromMemoryCompressedTTF(builtinFontM[settings.patFont],builtinFontMLen[settings.patFont],e->getConfInt("patFontSize",18)*dpiScale,NULL,upTo800))==NULL) {
+        if ((patFont=ImGui::GetIO().Fonts->AddFontFromMemoryCompressedTTF(builtinFontM[settings.patFont],builtinFontMLen[settings.patFont],MAX(1,e->getConfInt("patFontSize",18)*dpiScale),NULL,upTo800))==NULL) {
           logE("could not load pattern font!");
           patFont=ImGui::GetIO().Fonts->AddFontDefault();
         }
@@ -3615,7 +3617,7 @@ void FurnaceGUI::applyUISettings(bool updateFonts) {
 
     // 0x39B = Λ
     static const ImWchar bigFontRange[]={0x20,0xFF,0x39b,0x39b,0};
-    if ((bigFont=ImGui::GetIO().Fonts->AddFontFromMemoryCompressedTTF(font_plexSans_compressed_data,font_plexSans_compressed_size,40*dpiScale,NULL,bigFontRange))==NULL) {
+    if ((bigFont=ImGui::GetIO().Fonts->AddFontFromMemoryCompressedTTF(font_plexSans_compressed_data,font_plexSans_compressed_size,MAX(1,40*dpiScale),NULL,bigFontRange))==NULL) {
       logE("could not load big UI font!");
     }