diff --git a/makefiles/Makefile.cpp.mk b/makefiles/Makefile.cpp.mk
index 039a511bfd..8e9af03bc0 100644
--- a/makefiles/Makefile.cpp.mk
+++ b/makefiles/Makefile.cpp.mk
@@ -208,6 +208,7 @@ $(TEMP_CPP_DIR)/$1/%: \
 	-$(MKDIR) $(TEMP_CPP_DIR)$S$1$S$$*
 
 $(TEMP_CPP_DIR)/$1/%/CMakeLists.txt: \
+ $(SRC_DIR)/ortools/$1/samples/%.cc \
  ${SRC_DIR}/ortools/cpp/CMakeLists.txt.in \
  | $(TEMP_CPP_DIR)/$1/%
 	$(COPY) ortools$Scpp$SCMakeLists.txt.in $(TEMP_CPP_DIR)$S$1$S$$*$SCMakeLists.txt
@@ -227,6 +228,7 @@ $(TEMP_CPP_DIR)/$1/%/%.cc: \
 
 rcpp_%: \
  cpp \
+ $(SRC_DIR)/ortools/$1/samples/%.cc \
  $(TEMP_CPP_DIR)/$1/%/CMakeLists.txt \
  $(TEMP_CPP_DIR)/$1/%/%.cc \
  FORCE
@@ -254,10 +256,15 @@ define cpp-example-target =
 $(TEMP_CPP_DIR)/$1: | $(TEMP_CPP_DIR)
 	-$(MKDIR) $(TEMP_CPP_DIR)$S$1
 
-$(TEMP_CPP_DIR)/$1/%: $(SRC_DIR)/examples/$1/%.cc | $(TEMP_CPP_DIR)/$1
+$(TEMP_CPP_DIR)/$1/%: \
+ $(SRC_DIR)/examples/$1/%.cc \
+ | $(TEMP_CPP_DIR)/$1
 	-$(MKDIR) $(TEMP_CPP_DIR)$S$1$S$$*
 
-$(TEMP_CPP_DIR)/$1/%/CMakeLists.txt: ${SRC_DIR}/ortools/cpp/CMakeLists.txt.in | $(TEMP_CPP_DIR)/$1/%
+$(TEMP_CPP_DIR)/$1/%/CMakeLists.txt: \
+ $(SRC_DIR)/examples/$1/%.cc \
+ ${SRC_DIR}/ortools/cpp/CMakeLists.txt.in \
+ | $(TEMP_CPP_DIR)/$1/%
 	$(COPY) ortools$Scpp$SCMakeLists.txt.in $(TEMP_CPP_DIR)$S$1$S$$*$SCMakeLists.txt
 	$(SED) -i -e 's/@CPP_NAME@/$$*/' \
  $(TEMP_CPP_DIR)$S$1$S$$*$SCMakeLists.txt
@@ -275,6 +282,7 @@ $(TEMP_CPP_DIR)/$1/%/%.cc: \
 
 rcpp_%: \
  cpp \
+ $(SRC_DIR)/examples/$1/%.cc \
  $(TEMP_CPP_DIR)/$1/%/CMakeLists.txt \
  $(TEMP_CPP_DIR)/$1/%/%.cc \
  FORCE
@@ -304,8 +312,8 @@ $(TEMP_CPP_DIR)/tests: | $(TEMP_CPP_DIR)
 	-$(MKDIR) $(TEMP_CPP_DIR)$Stests
 
 $(TEMP_CPP_DIR)/tests/%: \
-	$(SRC_DIR)/examples/tests/%.cc \
-	| $(TEMP_CPP_DIR)/tests
+ $(SRC_DIR)/examples/tests/%.cc \
+ | $(TEMP_CPP_DIR)/tests
 	-$(MKDIR) $(TEMP_CPP_DIR)$Stests$S$*
 
 $(TEMP_CPP_DIR)/tests/%/CMakeLists.txt: ${SRC_DIR}/ortools/cpp/CMakeLists.txt.in | $(TEMP_CPP_DIR)/tests/%
@@ -326,6 +334,7 @@ $(TEMP_CPP_DIR)/tests/%/%.cc: \
 
 rcpp_%: \
  cpp \
+ $(SRC_DIR)/examples/tests/%.cc \
  $(TEMP_CPP_DIR)/tests/%/CMakeLists.txt \
  $(TEMP_CPP_DIR)/tests/%/%.cc \
  FORCE
diff --git a/makefiles/Makefile.dotnet.mk b/makefiles/Makefile.dotnet.mk
index 7f875cee5e..4f0c7a045f 100644
--- a/makefiles/Makefile.dotnet.mk
+++ b/makefiles/Makefile.dotnet.mk
@@ -143,6 +143,7 @@ $(TEMP_DOTNET_DIR)/$1/%/%.cs: \
 
 rdotnet_%: \
  dotnet \
+ $(SRC_DIR)/ortools/$1/samples/%.cs \
  $(TEMP_DOTNET_DIR)/$1/%/%.csproj \
  $(TEMP_DOTNET_DIR)/$1/%/%.cs \
  FORCE
@@ -212,6 +213,7 @@ $(TEMP_DOTNET_DIR)/$1/%/%.cs: \
 
 rdotnet_%: \
  dotnet \
+ $(SRC_DIR)/examples/$1/%.cs \
  $(TEMP_DOTNET_DIR)/$1/%/%.csproj \
  $(TEMP_DOTNET_DIR)/$1/%/%.cs \
  FORCE
@@ -280,6 +282,7 @@ $(TEMP_DOTNET_DIR)/$1/%/%.cs: \
 
 rdotnet_%: \
  dotnet \
+ $(SRC_DIR)/ortools/$1/csharp/%.cs \
  $(TEMP_DOTNET_DIR)/$1/%/%.csproj \
  $(TEMP_DOTNET_DIR)/$1/%/%.cs \
  FORCE
diff --git a/makefiles/Makefile.java.mk b/makefiles/Makefile.java.mk
index f48a2749c2..2ea2936a83 100644
--- a/makefiles/Makefile.java.mk
+++ b/makefiles/Makefile.java.mk
@@ -168,6 +168,7 @@ $(TEMP_JAVA_DIR)/$1/%/$(JAVA_SRC_DIR)/%.java: \
 
 rjava_%: \
  java \
+ $(SRC_DIR)/ortools/$1/samples/%.java \
  $(TEMP_JAVA_DIR)/$1/%/pom.xml \
  $(TEMP_JAVA_DIR)/$1/%/$(JAVA_SRC_DIR)/%.java \
  FORCE
@@ -219,6 +220,7 @@ $(TEMP_JAVA_DIR)/$1/%/$(JAVA_SRC_DIR)/%.java: \
 
 rjava_%: \
  java \
+ $(SRC_DIR)/examples/$1/%.java \
  $(TEMP_JAVA_DIR)/$1/%/pom.xml \
  $(TEMP_JAVA_DIR)/$1/%/$(JAVA_SRC_DIR)/%.java \
  FORCE
@@ -265,6 +267,7 @@ $(TEMP_JAVA_DIR)/$1/%/$(JAVA_TEST_DIR)/%.java: \
 
 rjava_%: \
  java \
+ $(SRC_DIR)/ortools/$1/java/%.java \
  $(TEMP_JAVA_DIR)/$1/%/pom.xml \
  $(TEMP_JAVA_DIR)/$1/%/$(JAVA_TEST_DIR)/%.java \
  FORCE