--- makefile.orig	2018-07-26 02:04:00 UTC
+++ makefile
@@ -77,7 +77,7 @@ INSTALL_DIRS = $(SOFA_LIB_DIR) $(SOFA_IN
 
 # Name the SOFA/C library in its source and target locations.
 
-SOFA_LIB_NAME = libsofa_c.a
+SOFA_LIB_NAME = libsofa_c.so
 SOFA_LIB = $(SOFA_LIB_DIR)$(SOFA_LIB_NAME)
 
 # Name the SOFA/C testbed in its source and target locations.
@@ -380,7 +380,7 @@ $(INSTALL_DIRS):
 
 # Build the library.
 $(SOFA_LIB_NAME): $(SOFA_OBS)
-	ar ru $(SOFA_LIB_NAME) $?
+	$(CC) -shared $(LDFLAGS) -o $(SOFA_LIB_NAME) $?
 
 # Install the header files.
 $(SOFA_INC) : $(INSTALL_DIRS) $(SOFA_INC_NAMES)