diff --git a/Makefile_geant4 b/Makefile_geant4
index b87fa81..1128776 100644
--- a/Makefile_geant4
+++ b/Makefile_geant4
@@ -15,6 +15,8 @@ else
     CMAKE = cmake3
 endif
 
+include $(BUILD_SCRIPTS)/geant4_version.mk
+
 all: $(G4DIR)/.make_install_done
 
 $(TARFILE):
@@ -33,6 +35,10 @@ $(G4DIR)/.patch_done: $(G4DIR)/.untar_done
 	    then patch Geant4ToolchainBackwardCompatibility.cmake \
 	        < $(BUILD_SCRIPTS)/patches/geant4/Geant4ToolchainBackwardCompatibility.cmake.patch; \
 	fi
+ifeq ($(GEANT4_EQ_10_04), true)
+	patch $(G4DIR)/config/sys/Linux-g++.gmk \
+	    < $(BUILD_SCRIPTS)/patches/geant4/Linux-g++.gmk.patch
+endif	
 	date > $@
 
 $(G4DIR)/.configure_done: $(G4DIR)/.patch_done
diff --git a/geant4_version.mk b/geant4_version.mk
new file mode 100644
index 0000000..637827b
--- /dev/null
+++ b/geant4_version.mk
@@ -0,0 +1,6 @@
+ifdef GEANT4_VERSION
+    GEANT4_MAJOR_VERSION := $(shell echo $(GEANT4_VERSION) | awk -F. '{print $$1}')
+    GEANT4_MINOR_VERSION := $(shell echo $(GEANT4_VERSION) | awk -F. '{print $$2}' | bc)
+    GEANT4_SUBMINOR_VERSION := $(shell echo $(GEANT4_VERSION) | awk -F'.p' '{print $$3}' | bc)
+    GEANT4_EQ_10_04 := $(shell if [[ $(GEANT4_MAJOR_VERSION) -eq 10 && $(GEANT4_MINOR_VERSION) -eq 4 ]]; then echo true; else echo false; fi)
+endif
diff --git a/patches/geant4/Linux-g++.gmk.patch b/patches/geant4/Linux-g++.gmk.patch
new file mode 100644
index 0000000..995478d
--- /dev/null
+++ b/patches/geant4/Linux-g++.gmk.patch
@@ -0,0 +1,49 @@
+--- Linux-g++.gmk.original	2021-09-22 14:45:22.608148649 -0400
++++ Linux-g++.gmk.patched	2021-09-22 16:22:16.414406962 -0400
+@@ -92,19 +92,15 @@
+     QTHOME     := /usr
+   endif
+   ifndef QTMOC
+-    QTMOC      := $(QTHOME)/bin/moc
++#    QTMOC      := $(shell if [ -f  "$(QTHOME)/bin/moc-qt5" ]; then echo $(QTHOME)/bin/moc-qt5; elif [ -f  "$(QTHOME)/bin/moc-qt4" ]; then echo $(QTHOME)/bin/moc-qt4; else echo $(QTHOME)/bin/moc; fi)
++    QTMOC      := dummy_value
+   endif
+ 
+-  QT_VERSION := $(shell $(QTMOC) 2>&1 -v | sed 's/.* .Qt \([0-9]\)\..*/\1/' )
++  QT_VERSION := $(shell $(QTMOC) -v | awk '{print $$2}' | awk -F. '{print $$1}')
+ 
+   ifeq ($(QT_VERSION),5)
+     ifndef QTFLAGS              # Qt5
+-      QTFLAGS   := -I $(QTHOME)/include -I$(QTHOME)/include/Qt
+-      QTFLAGS   += -I $(QTHOME)/include/QtCore
+-      QTFLAGS   += -I $(QTHOME)/include/QtGui
+-      QTFLAGS   += -I $(QTHOME)/include/QtWidgets
+-      QTFLAGS   += -I $(QTHOME)/include/QtOpenGL
+-      QTFLAGS   += -I $(QTHOME)/include/QtPrintSupport
++      QTFLAGS   := -I $(QTHOME)/include -I$(QTHOME)/include/Qt5
+     endif
+   else                          # Qt4
+     ifndef QTFLAGS
+@@ -115,18 +111,18 @@
+     endif
+   endif
+   ifndef QTLIBPATH
+-    QTLIBPATH := $(QTHOME)/lib
++    QTLIBPATH := $(QTHOME)/lib64
+     QT_SEARCH_LIB := $(shell ls  $(QTLIBPATH)/qt$(QT_VERSION)/libq* 2>/dev/null | wc -l )
+     ifneq ($(QT_SEARCH_LIB),0)
+-      QTLIBPATH := $(QTHOME)/lib/qt$(QT_VERSION)
++      QTLIBPATH := $(QTHOME)/lib64/qt$(QT_VERSION)
+     endif
+   endif
+   ifeq ($(QT_VERSION),5)
+     ifndef QTLIBS              # Qt5
+-      QTLIBS   := -L$(QTLIBPATH) -lQtCore -lQtGui -lQtWidgets -lQtPrintSupport
++      QTLIBS   := -L$(QTLIBPATH) -lQt5Core -lQt5Gui -lQt5Widgets -lQt5PrintSupport
+     endif
+     ifndef GLQTLIBS
+-      GLQTLIBS := -L$(QTLIBPATH) -lQtCore -lQtGui -lQtWidgets  -lQtOpenGL -lQtPrintSupport
++      GLQTLIBS := -L$(QTLIBPATH) -lQt5Core -lQt5Gui -lQt5Widgets  -lQt5OpenGL -lQt5PrintSupport
+     endif
+   else                         # Qt4
+     ifndef QTLIBS