diff --git a/Makefile.local b/Makefile.local
index 0f99e3f9..79ac50d4 100644
--- a/Makefile.local
+++ b/Makefile.local
@@ -199,7 +199,7 @@ notmuch_client_modules = $(notmuch_client_srcs:.c=.o)
 notmuch: $(notmuch_client_modules) lib/libnotmuch.a
 	$(call quiet,CXX $(CFLAGS)) $^ $(FINAL_LIBNOTMUCH_LDFLAGS) -o $@
 
-notmuch-shared: $(notmuch_client_modules) lib/libnotmuch.so
+notmuch-shared: $(notmuch_client_modules) lib/$(LINKER_NAME)
 	$(call quiet,CXX $(CFLAGS)) $(notmuch_client_modules) $(FINAL_NOTMUCH_LDFLAGS) -o $@
 
 notmuch.1.gz: notmuch.1
diff --git a/configure b/configure
index 90a399ca..8af3dc9e 100755
--- a/configure
+++ b/configure
@@ -234,6 +234,15 @@ else
     have_emacs=0
 fi
 
+printf "Checking for Mac OS X (for shared library)... "
+if [ `uname` = "Darwin" ] ; then
+    printf "Yes.\n"
+    mac_os_x=1
+else
+    printf "No.\n"
+    mac_os_x=0
+fi
+
 if [ $errors -gt 0 ]; then
     cat <<EOF
 
@@ -399,6 +408,10 @@ HAVE_GETLINE = ${have_getline}
 # build its own version)
 HAVE_STRCASESTR = ${have_strcasestr}
 
+# Whether we are building on OS X.  This will affect how we build the
+# shared library.
+MAC_OS_X = ${mac_os_x}
+
 # Flags needed to compile and link against Xapian
 XAPIAN_CXXFLAGS = ${xapian_cxxflags}
 XAPIAN_LDFLAGS = ${xapian_ldflags}
diff --git a/lib/Makefile.local b/lib/Makefile.local
index dc608ef0..f001e75b 100644
--- a/lib/Makefile.local
+++ b/lib/Makefile.local
@@ -22,9 +22,20 @@ LIBNOTMUCH_VERSION_MINOR = 0
 # simply compatible changes to the implementation).
 LIBNOTMUCH_VERSION_RELEASE = 0
 
-LINKER_NAME = libnotmuch.so
+ifeq ($(MAC_OS_X),1)
+LIBRARY_SUFFIX = dylib
+# On OS X, library version numbers go before suffix.
+LINKER_NAME = libnotmuch.$(LIBRARY_SUFFIX)
+SONAME = libnotmuch.$(LIBNOTMUCH_VERSION_MAJOR).$(LIBRARY_SUFFIX)
+LIBNAME = libnotmuch.$(LIBNOTMUCH_VERSION_MAJOR).$(LIBNOTMUCH_VERSION_MINOR).$(LIBNOTMUCH_VERSION_RELEASE).$(LIBRARY_SUFFIX)
+LIBRARY_LINK_FLAG = -Wl,-dylib_install_name -Wl,$(SONAME)
+else
+LIBRARY_SUFFIX = so
+LINKER_NAME = libnotmuch.$(LIBRARY_SUFFIX)
 SONAME = $(LINKER_NAME).$(LIBNOTMUCH_VERSION_MAJOR)
 LIBNAME = $(SONAME).$(LIBNOTMUCH_VERSION_MINOR).$(LIBNOTMUCH_VERSION_RELEASE)
+LIBRARY_LINK_FLAG = -Wl,-soname=$(SONAME)
+endif
 
 dir := lib
 extra_cflags += -I$(dir) -fPIC
@@ -52,7 +63,7 @@ $(dir)/libnotmuch.a: $(libnotmuch_modules)
 	$(call quiet,AR) rcs $@ $^
 
 $(dir)/$(LIBNAME): $(libnotmuch_modules)
-	$(call quiet,CXX $(CXXFLAGS)) $^ $(FINAL_LIBNOTMUCH_LDFLAGS) -shared -Wl,-soname=$(SONAME) -o $@
+	$(call quiet,CXX $(CXXFLAGS)) $^ $(FINAL_LIBNOTMUCH_LDFLAGS) -shared $(LIBRARY_LINK_FLAG) -o $@
 
 $(dir)/$(SONAME): $(dir)/$(LIBNAME)
 	ln -sf $(LIBNAME) $@