diff --git a/src/Makevars b/src/Makevars
index b2b4c0a3..470fdd52 100644
--- a/src/Makevars
+++ b/src/Makevars
@@ -23,10 +23,10 @@ $(STATLIB):
 	# therefore is only used if cargo is absent from the user's PATH.
 	if [ "$(NOT_CRAN)" != "true" ]; then \
 		export CARGO_HOME=$(CARGOTMP); \
-		export CARGO_BUILD_JOBS=2; \
+		export _CARGO_CRAN_OPTIONS="-j 2"; \
 	fi && \
 		export PATH="$(PATH):$(HOME)/.cargo/bin" && \
-		cargo build --lib --release --manifest-path=./rust/Cargo.toml --target-dir $(TARGET_DIR)
+		cargo build ${_CARGO_CRAN_OPTIONS} --lib --release --manifest-path=./rust/Cargo.toml --target-dir $(TARGET_DIR)
 	if [ "$(NOT_CRAN)" != "true" ]; then \
 		rm -Rf $(CARGOTMP) $(VENDOR_DIR) $(LIBDIR)/build; \
 	fi
diff --git a/src/Makevars.win b/src/Makevars.win
index 0888a24f..62e3a271 100644
--- a/src/Makevars.win
+++ b/src/Makevars.win
@@ -32,11 +32,11 @@ $(STATLIB):
 	# CARGO_LINKER is provided in Makevars.ucrt for R >= 4.2
 	if [ "$(NOT_CRAN)" != "true" ]; then \
 		export CARGO_HOME=$(CARGOTMP); \
-		export CARGO_BUILD_JOBS=2; \
+		export _CARGO_CRAN_OPTIONS="-j 2"; \
 	fi && \
 		export CARGO_TARGET_X86_64_PC_WINDOWS_GNU_LINKER="$(CARGO_LINKER)" && \
 		export LIBRARY_PATH="$${LIBRARY_PATH};$(CURDIR)/$(TARGET_DIR)/libgcc_mock" && \
-		cargo build --target=$(TARGET) --lib --release --manifest-path=./rust/Cargo.toml --target-dir $(TARGET_DIR)
+		cargo build ${_CARGO_CRAN_OPTIONS} --target=$(TARGET) --lib --release --manifest-path=./rust/Cargo.toml --target-dir $(TARGET_DIR)
 	if [ "$(NOT_CRAN)" != "true" ]; then \
 		rm -Rf $(CARGOTMP) $(VENDOR_DIR) $(LIBDIR)/build; \
 	fi