--- src/c/Makefile.in.orig	2020-07-01 14:39:48.097395278 -0600
+++ src/c/Makefile.in	2020-07-06 21:07:09.618570350 -0600
@@ -92,6 +92,46 @@ all: $(DPP) ../libeclmin.a ../cinit.o
 # 	if test -f ../CROSS-DPP ; then ../CROSS-DPP $< $@.c ; else $(DPP) $< $@.c ; fi
 # 	$(CC) -DECLDIR="\"@ecldir@\"" $(CFLAGS) -S -o $@ $@.c
 
+# GCC doesn't understand #pragma STDC FENV_ACCESS ON, so we do this instead:
+numbers/atan.o: numbers/atan.c
+	$(CC) -DECLDIR="\"@ecldir@\"" $(CFLAGS) -frounding-math -fsignaling-nans -o $@ $<
+numbers/ceiling.o: numbers/ceiling.c
+	$(CC) -DECLDIR="\"@ecldir@\"" $(CFLAGS) -frounding-math -fsignaling-nans -o $@ $<
+numbers/cos.o: numbers/cos.c
+	$(CC) -DECLDIR="\"@ecldir@\"" $(CFLAGS) -frounding-math -fsignaling-nans -o $@ $<
+numbers/cosh.o: numbers/cosh.c
+	$(CC) -DECLDIR="\"@ecldir@\"" $(CFLAGS) -frounding-math -fsignaling-nans -o $@ $<
+numbers/divide.o: numbers/divide.c
+	$(CC) -DECLDIR="\"@ecldir@\"" $(CFLAGS) -frounding-math -fsignaling-nans -o $@ $<
+numbers/exp.o: numbers/exp.c
+	$(CC) -DECLDIR="\"@ecldir@\"" $(CFLAGS) -frounding-math -fsignaling-nans -o $@ $<
+numbers/expt.o: numbers/expt.c
+	$(CC) -DECLDIR="\"@ecldir@\"" $(CFLAGS) -frounding-math -fsignaling-nans -o $@ $<
+numbers/floor.o: numbers/floor.c
+	$(CC) -DECLDIR="\"@ecldir@\"" $(CFLAGS) -frounding-math -fsignaling-nans -o $@ $<
+numbers/log.o: numbers/log.c
+	$(CC) -DECLDIR="\"@ecldir@\"" $(CFLAGS) -frounding-math -fsignaling-nans -o $@ $<
+numbers/minus.o: numbers/minus.c
+	$(CC) -DECLDIR="\"@ecldir@\"" $(CFLAGS) -frounding-math -fsignaling-nans -o $@ $<
+numbers/plus.o: numbers/plus.c
+	$(CC) -DECLDIR="\"@ecldir@\"" $(CFLAGS) -frounding-math -fsignaling-nans -o $@ $<
+numbers/round.o: numbers/round.c
+	$(CC) -DECLDIR="\"@ecldir@\"" $(CFLAGS) -frounding-math -fsignaling-nans -o $@ $<
+numbers/sin.o: numbers/sin.c
+	$(CC) -DECLDIR="\"@ecldir@\"" $(CFLAGS) -frounding-math -fsignaling-nans -o $@ $<
+numbers/sinh.o: numbers/sinh.c
+	$(CC) -DECLDIR="\"@ecldir@\"" $(CFLAGS) -frounding-math -fsignaling-nans -o $@ $<
+numbers/sqrt.o: numbers/sqrt.c
+	$(CC) -DECLDIR="\"@ecldir@\"" $(CFLAGS) -frounding-math -fsignaling-nans -o $@ $<
+numbers/tan.o: numbers/tan.c
+	$(CC) -DECLDIR="\"@ecldir@\"" $(CFLAGS) -frounding-math -fsignaling-nans -o $@ $<
+numbers/tanh.o: numbers/tanh.c
+	$(CC) -DECLDIR="\"@ecldir@\"" $(CFLAGS) -frounding-math -fsignaling-nans -o $@ $<
+numbers/times.o: numbers/times.c
+	$(CC) -DECLDIR="\"@ecldir@\"" $(CFLAGS) -frounding-math -fsignaling-nans -o $@ $<
+numbers/truncate.o: numbers/truncate.c
+	$(CC) -DECLDIR="\"@ecldir@\"" $(CFLAGS) -frounding-math -fsignaling-nans -o $@ $<
+
 ../libeclmin.a: $(OBJS) all_symbols.o all_symbols2.o
 	$(RM) $@
 	$(AR) cr $@ $(OBJS)