diff --git a/src/slic3r/GUI/FirmwareDialog.cpp b/src/slic3r/GUI/FirmwareDialog.cpp
index 2df1f0bc9..90e2cbc9c 100644
--- a/src/slic3r/GUI/FirmwareDialog.cpp
+++ b/src/slic3r/GUI/FirmwareDialog.cpp
@@ -13,6 +13,7 @@
 #include "libslic3r/Utils.hpp"
 #include "avrdude/avrdude-slic3r.hpp"
 #include "GUI.hpp"
+#include "GUI_App.hpp"
 #include "I18N.hpp"
 #include "MsgDialog.hpp"
 #include "../Utils/HexFile.hpp"
@@ -36,7 +37,6 @@
 #include <wx/collpane.h>
 #include <wx/msgdlg.h>
 #include <wx/filefn.h>
-#include "GUI_App.hpp"
 
 
 namespace fs = boost::filesystem;
@@ -693,11 +693,16 @@ FirmwareDialog::FirmwareDialog(wxWindow *parent) :
 	enum {
 		DIALOG_MARGIN = 15,
 		SPACING = 10,
-		MIN_WIDTH = 600,
-		MIN_HEIGHT = 200,
-		MIN_HEIGHT_EXPANDED = 500,
+		MIN_WIDTH = 50,
+		MIN_HEIGHT = 18,
+		MIN_HEIGHT_EXPANDED = 40,
 	};
 
+	const int em = GUI::wxGetApp().em_unit();
+	int min_width = MIN_WIDTH * em;
+	int min_height = MIN_HEIGHT * em;
+	int min_height_expanded = MIN_HEIGHT_EXPANDED * em;
+
 	wxFont status_font = wxSystemSettings::GetFont(wxSYS_DEFAULT_GUI_FONT);
 	status_font.MakeBold();
 	wxFont mono_font(wxFontInfo().Family(wxFONTFAMILY_TELETYPE));
@@ -769,10 +774,10 @@ FirmwareDialog::FirmwareDialog(wxWindow *parent) :
 
 	auto *topsizer = new wxBoxSizer(wxVERTICAL);
 	topsizer->Add(panel, 1, wxEXPAND | wxALL, DIALOG_MARGIN);
-	SetMinSize(wxSize(MIN_WIDTH, MIN_HEIGHT));
+	SetMinSize(wxSize(min_width, min_height));
 	SetSizerAndFit(topsizer);
 	const auto size = GetSize();
-	SetSize(std::max(size.GetWidth(), static_cast<int>(MIN_WIDTH)), std::max(size.GetHeight(), static_cast<int>(MIN_HEIGHT)));
+	SetSize(std::max(size.GetWidth(), static_cast<int>(min_width)), std::max(size.GetHeight(), static_cast<int>(min_height)));
 	Layout();
 
     SetEscapeId(wxID_CLOSE); // To close the dialog using "Esc" button
@@ -786,13 +791,13 @@ FirmwareDialog::FirmwareDialog(wxWindow *parent) :
 		}
 	});
 
-	p->spoiler->Bind(wxEVT_COLLAPSIBLEPANE_CHANGED, [this](wxCollapsiblePaneEvent &evt) {
+	p->spoiler->Bind(wxEVT_COLLAPSIBLEPANE_CHANGED, [=](wxCollapsiblePaneEvent &evt) {
 		if (evt.GetCollapsed()) {
-			this->SetMinSize(wxSize(MIN_WIDTH, MIN_HEIGHT));
+			this->SetMinSize(wxSize(min_width, min_height));
 			const auto new_height = this->GetSize().GetHeight() - this->p->txt_stdout->GetSize().GetHeight();
 			this->SetSize(this->GetSize().GetWidth(), new_height);
 		} else {
-			this->SetMinSize(wxSize(MIN_WIDTH, MIN_HEIGHT_EXPANDED));
+			this->SetMinSize(wxSize(min_width, min_height_expanded));
 		}
 
 		this->Layout();
diff --git a/src/slic3r/GUI/GUI_App.cpp b/src/slic3r/GUI/GUI_App.cpp
index 0e1f73a1a..1847b2898 100644
--- a/src/slic3r/GUI/GUI_App.cpp
+++ b/src/slic3r/GUI/GUI_App.cpp
@@ -78,6 +78,7 @@ IMPLEMENT_APP(GUI_App)
 
 GUI_App::GUI_App()
     : wxApp()
+    , m_em_unit(10)
 #if ENABLE_IMGUI
     , m_imgui(new ImGuiWrapper())
 #endif // ENABLE_IMGUI
diff --git a/src/slic3r/GUI/MsgDialog.hpp b/src/slic3r/GUI/MsgDialog.hpp
index a5af6afe2..09bb89e4f 100644
--- a/src/slic3r/GUI/MsgDialog.hpp
+++ b/src/slic3r/GUI/MsgDialog.hpp
@@ -32,8 +32,8 @@ struct MsgDialog : wxDialog
 
 protected:
 	enum {
-		CONTENT_WIDTH = 50,//500,
-		CONTENT_MAX_HEIGHT = 60,//600,
+		CONTENT_WIDTH = 50,
+		CONTENT_MAX_HEIGHT = 60,
 		BORDER = 30,
 		VERT_SPACING = 15,
 		HORIZ_SPACING = 5,
diff --git a/src/slic3r/GUI/PrintHostDialogs.cpp b/src/slic3r/GUI/PrintHostDialogs.cpp
index 6dfa11889..0d70027c0 100644
--- a/src/slic3r/GUI/PrintHostDialogs.cpp
+++ b/src/slic3r/GUI/PrintHostDialogs.cpp
@@ -38,7 +38,7 @@ PrintHostSendDialog::PrintHostSendDialog(const fs::path &path)
 #endif
 
     auto *label_dir_hint = new wxStaticText(this, wxID_ANY, _(L("Use forward slashes ( / ) as a directory separator if needed.")));
-    label_dir_hint->Wrap(CONTENT_WIDTH);
+    label_dir_hint->Wrap(CONTENT_WIDTH * wxGetApp().em_unit());
 
     content_sizer->Add(txt_filename, 0, wxEXPAND);
     content_sizer->Add(label_dir_hint);
@@ -135,10 +135,11 @@ PrintHostQueueDialog::PrintHostQueueDialog(wxWindow *parent)
     , on_error_evt(this, EVT_PRINTHOST_ERROR, &PrintHostQueueDialog::on_error, this)
     , on_cancel_evt(this, EVT_PRINTHOST_CANCEL, &PrintHostQueueDialog::on_cancel, this)
 {
-    enum { HEIGHT = 800, WIDTH = 400, SPACING = 5 };
+    enum { HEIGHT = 60, WIDTH = 30, SPACING = 5 };
 
-    SetSize(wxSize(HEIGHT, WIDTH));
-    SetSize(GetMinSize());
+    const auto em = GetTextExtent("m").x;
+
+    SetSize(wxSize(HEIGHT * em, WIDTH * em));
 
     auto *topsizer = new wxBoxSizer(wxVERTICAL);
 
diff --git a/src/slic3r/GUI/UpdateDialogs.cpp b/src/slic3r/GUI/UpdateDialogs.cpp
index 346a9e231..c4b78eb1a 100644
--- a/src/slic3r/GUI/UpdateDialogs.cpp
+++ b/src/slic3r/GUI/UpdateDialogs.cpp
@@ -12,6 +12,7 @@
 #include "libslic3r/libslic3r.h"
 #include "libslic3r/Utils.hpp"
 #include "GUI.hpp"
+#include "GUI_App.hpp"
 #include "I18N.hpp"
 #include "ConfigWizard.hpp"
 
@@ -34,7 +35,8 @@ MsgUpdateSlic3r::MsgUpdateSlic3r(const Semver &ver_current, const Semver &ver_on
 
 	auto *text = new wxStaticText(this, wxID_ANY, _(L("To download, follow the link below.")));
 	const auto link_width = link->GetSize().GetWidth();
-	text->Wrap(CONTENT_WIDTH > link_width ? CONTENT_WIDTH : link_width);
+	const int content_width = CONTENT_WIDTH * wxGetApp().em_unit();
+	text->Wrap(content_width > link_width ? content_width : link_width);
 	content_sizer->Add(text);
 	content_sizer->AddSpacer(VERT_SPACING);
 
@@ -75,7 +77,7 @@ MsgUpdateConfig::MsgUpdateConfig(const std::unordered_map<std::string, std::stri
 		"should there be a problem with the new version.\n\n"
 		"Updated configuration bundles:"
 	)));
-	text->Wrap(CONTENT_WIDTH);
+	text->Wrap(CONTENT_WIDTH * wxGetApp().em_unit());
 	content_sizer->Add(text);
 	content_sizer->AddSpacer(VERT_SPACING);
 
@@ -115,16 +117,16 @@ MsgDataIncompatible::MsgDataIncompatible(const std::unordered_map<std::string, w
 		"You may either exit Slic3r and try again with a newer version, or you may re-run the initial configuration. "
 		"Doing so will create a backup snapshot of the existing configuration before installing files compatible with this Slic3r.\n"
 	)));
-	text->Wrap(CONTENT_WIDTH);
+	text->Wrap(CONTENT_WIDTH * wxGetApp().em_unit());
 	content_sizer->Add(text);
 
 	auto *text2 = new wxStaticText(this, wxID_ANY, wxString::Format(_(L("This Slic3r PE version: %s")), SLIC3R_VERSION));
-	text2->Wrap(CONTENT_WIDTH);
+	text2->Wrap(CONTENT_WIDTH * wxGetApp().em_unit());
 	content_sizer->Add(text2);
 	content_sizer->AddSpacer(VERT_SPACING);
 
 	auto *text3 = new wxStaticText(this, wxID_ANY, _(L("Incompatible bundles:")));
-	text3->Wrap(CONTENT_WIDTH);
+	text3->Wrap(CONTENT_WIDTH * wxGetApp().em_unit());
 	content_sizer->Add(text3);
 	content_sizer->AddSpacer(VERT_SPACING);
 
@@ -175,7 +177,7 @@ MsgDataLegacy::MsgDataLegacy() :
 		)),
 		ConfigWizard::name()
 	));
-	text->Wrap(CONTENT_WIDTH);
+	text->Wrap(CONTENT_WIDTH * wxGetApp().em_unit());
 	content_sizer->Add(text);
 	content_sizer->AddSpacer(VERT_SPACING);