add options to readme
diff --git a/INSTALL.md b/INSTALL.md
index 2106d51..8c4f24b 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -13,10 +13,18 @@
 
 Configure with non-standard settings:
 
-asn1c specific ./configure options include:
+asn1c-specific ./configure options include:
 
-    --enable-Werror
-    --enable-ASN_DEBUG
+  Option                 | Description
+------------------------ | ---------------------------------------------------
+  --enable-ASN_DEBUG     | produce debug log during `make check` testing
+  --enable-code-coverage | whether to enable code coverage support
+  --enable-Werror        | abort compilation after any C compiler warning
+  --enable-test-Werror   | abort compiling tests after any C compiler warning
+  --enable-test-32bit    | enable tests for 32-bit compatibility
+  --disable-test-ubsan   | disable Undefined Behavior Sanitizer for tests
+  --disable-test-asan    | disable Address Sanitizer for tests
+  --enable-test-fuzzer   | enable LLVM LibFuzzer for randomized testing
 
 invoke `./configure --help` for details.
 
diff --git a/configure.ac b/configure.ac
index 1907927..6a0f062 100644
--- a/configure.ac
+++ b/configure.ac
@@ -129,7 +129,7 @@
 dnl treat it like a special case to be checked.
 AC_ARG_ENABLE([test-32bit],
     [AS_HELP_STRING([--enable-test-32bit],
-    [Enable tests for 32-bit compatibility])],
+    [enable tests for 32-bit compatibility])],
     [enable_test_32bit=$enableval], [enable_test_32bit=no])
 AS_IF([test "x$enable_test_32bit" != xno], [
     AX_CHECK_COMPILE_FLAG([-m32], [CFLAGS_M32="-m32 -DEXPLICIT_32BIT"],
@@ -146,7 +146,7 @@
 dnl Enable Undefined Behavior Sanitizer, if supported.
 AC_ARG_ENABLE([test-ubsan],
     [AS_HELP_STRING([--disable-test-ubsan],
-        [Disable Undefined Behavior Sanitizer for tests])],
+        [disable Undefined Behavior Sanitizer for tests])],
     [disable_test_ubsan=$enableval], [disable_test_ubsan=maybe])
 AS_IF([test "x$disable_test_ubsan" != xno], [
     AX_CHECK_COMPILE_AND_LINK_FLAG([-fsanitize=undefined],
@@ -187,7 +187,7 @@
 ASAN_ENV_FLAGS=""
 AC_ARG_ENABLE([test-asan],
     [AS_HELP_STRING([--disable-test-asan],
-        [Disable Address Sanitizer for tests])],
+        [disable Address Sanitizer for tests])],
     [disable_test_asan=$enableval], [disable_test_asan=maybe])
 AS_IF([test "x$disable_test_asan" != xno], [
     AX_CHECK_COMPILE_AND_LINK_FLAG([-fsanitize=address],
@@ -223,7 +223,7 @@
 LIBFUZZER_CFLAGS=""
 AC_ARG_ENABLE([test-fuzzer],
     [AS_HELP_STRING([--enable-test-fuzzer],
-        [Enable LLVM LibFuzzer for randomized testing])],
+        [enable LLVM LibFuzzer for randomized testing])],
     [enable_test_fuzzer=$enableval], [enable_test_fuzzer=no])
 AS_IF([test "x$enable_test_fuzzer" != xno], [
     AX_CHECK_COMPILE_AND_LINK_FLAG([-fsanitize=fuzzer],
diff --git a/m4/ax_code_coverage.m4 b/m4/ax_code_coverage.m4
index 9618bda..869d470 100644
--- a/m4/ax_code_coverage.m4
+++ b/m4/ax_code_coverage.m4
@@ -85,7 +85,7 @@
 	AC_MSG_CHECKING([whether to build with code coverage support])
 	AC_ARG_ENABLE([code-coverage],
 	  AS_HELP_STRING([--enable-code-coverage],
-	  [Whether to enable code coverage support]),,
+	  [enable code coverage statistics collection]),,
 	  enable_code_coverage=no)
 
 	AM_CONDITIONAL([CODE_COVERAGE_ENABLED], [test x$enable_code_coverage = xyes])