diff --git a/main.sh b/main.sh
index 461093d..85e9b76 100755
--- a/main.sh
+++ b/main.sh
@@ -131,36 +131,44 @@ EOF
 
 # Translate usage string -> getopts arguments, and set $arg_<flag> defaults
 while read __b3bp_tmp_line; do
-  # fetch single character version of option string
-  __b3bp_tmp_opt="$(echo "${__b3bp_tmp_line}" |awk '{print $1}' |sed -e 's#^-##')"
+  if echo "${__b3bp_tmp_line}" |egrep '^-' >/dev/null 2>&1; then
+    # fetch single character version of option string
+    __b3bp_tmp_opt="$(echo "${__b3bp_tmp_line}" |awk '{print $1}' |sed -e 's#^-##')"
 
-  # fetch long version if present
-  __b3bp_tmp_long_opt="$(echo "${__b3bp_tmp_line}" |awk '/\-\-/ {print $2}' |sed -e 's#^--##')"
-  __b3bp_tmp_long_opt_mangled="$(sed 's#-#_#g' <<< $__b3bp_tmp_long_opt)"
+    # fetch long version if present
+    __b3bp_tmp_long_opt="$(echo "${__b3bp_tmp_line}" |awk '/\-\-/ {print $2}' |sed -e 's#^--##')"
+    __b3bp_tmp_long_opt_mangled="$(sed 's#-#_#g' <<< $__b3bp_tmp_long_opt)"
 
-  # map long name back to short name
-  __b3bp_tmp_varname="__b3bp_tmp_short_opt_${__b3bp_tmp_long_opt_mangled}"
-  eval "${__b3bp_tmp_varname}=\"${__b3bp_tmp_opt}\""
+    # map long name back to short name
+    __b3bp_tmp_varname="__b3bp_tmp_short_opt_${__b3bp_tmp_long_opt_mangled}"
+    eval "${__b3bp_tmp_varname}=\"${__b3bp_tmp_opt}\""
 
-  # check if option takes an argument
-  __b3bp_tmp_varname="__b3bp_tmp_has_arg_${__b3bp_tmp_opt}"
-  if ! echo "${__b3bp_tmp_line}" |egrep '\[.*\]' >/dev/null 2>&1; then
-    __b3bp_tmp_init="0" # it's a flag. init with 0
-    eval "${__b3bp_tmp_varname}=0"
-  else
-    __b3bp_tmp_opt="${__b3bp_tmp_opt}:" # add : if opt has arg
-    __b3bp_tmp_init=""  # it has an arg. init with ""
-    eval "${__b3bp_tmp_varname}=1"
+    # check if option takes an argument
+    __b3bp_tmp_varname="__b3bp_tmp_has_arg_${__b3bp_tmp_opt}"
+    if ! echo "${__b3bp_tmp_line}" |egrep '\[.*\]' >/dev/null 2>&1; then
+      __b3bp_tmp_init="0" # it's a flag. init with 0
+      eval "${__b3bp_tmp_varname}=0"
+    else
+      __b3bp_tmp_opt="${__b3bp_tmp_opt}:" # add : if opt has arg
+      __b3bp_tmp_init=""  # it has an arg. init with ""
+      eval "${__b3bp_tmp_varname}=1"
+    fi
+    __b3bp_tmp_opts="${__b3bp_tmp_opts:-}${__b3bp_tmp_opt}"
+  fi
+
+  [ -z "${__b3bp_tmp_opt:-}" ] && continue
+
+  if echo "${__b3bp_tmp_line}" |egrep '\. Default=' >/dev/null 2>&1; then
+    # ignore default value if option does not have an argument
+    __b3bp_tmp_varname="__b3bp_tmp_has_arg_${__b3bp_tmp_opt:0:1}"
+
+    if [ "${!__b3bp_tmp_varname}" = "1" ]; then
+      __b3bp_tmp_init="$(echo "${__b3bp_tmp_line}" |sed 's#^.*Default=\(\)#\1#g')"
+    fi
   fi
-  __b3bp_tmp_opts="${__b3bp_tmp_opts:-}${__b3bp_tmp_opt}"
 
   __b3bp_tmp_varname="arg_${__b3bp_tmp_opt:0:1}"
-  if ! echo "${__b3bp_tmp_line}" |egrep '\. Default=' >/dev/null 2>&1; then
-    eval "${__b3bp_tmp_varname}=\"${__b3bp_tmp_init}\""
-  else
-    __b3bp_tmp_match="$(echo "${__b3bp_tmp_line}" |sed 's#^.*Default=\(\)#\1#g')"
-    eval "${__b3bp_tmp_varname}=\"${__b3bp_tmp_match}\""
-  fi
+  eval "${__b3bp_tmp_varname}=\"${__b3bp_tmp_init}\""
 done <<< "${__usage:-}"
 
 # run getopts only if options were specified in __usage
diff --git a/test/fixture/main-usage-defaults.exitcode b/test/fixture/main-usage-defaults.exitcode
new file mode 100644
index 0000000..573541a
--- /dev/null
+++ b/test/fixture/main-usage-defaults.exitcode
@@ -0,0 +1 @@
+0
diff --git a/test/fixture/main-usage-defaults.stdio b/test/fixture/main-usage-defaults.stdio
new file mode 100644
index 0000000..380792a
--- /dev/null
+++ b/test/fixture/main-usage-defaults.stdio
@@ -0,0 +1,7 @@
+ACCPTST:STDIO_REPLACE_DATETIMES
+{datetime} UTC [     info] arg_1: 0
+{datetime} UTC [     info] arg_2: 0
+{datetime} UTC [     info] arg_3: THREE
+{datetime} UTC [     info] arg_4: FOUR
+{datetime} UTC [     info] arg_5: OOOPS
+{datetime} UTC [     info] arg_6: 
diff --git a/test/scenario/main-usage-defaults/run.sh b/test/scenario/main-usage-defaults/run.sh
new file mode 100755
index 0000000..0b37c8c
--- /dev/null
+++ b/test/scenario/main-usage-defaults/run.sh
@@ -0,0 +1,33 @@
+#!/usr/bin/env bash
+set -o pipefail
+set -o errexit
+set -o nounset
+# set -o xtrace
+
+# Set magic variables for current FILE & DIR
+__dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+__file="${__dir}/$(basename "${BASH_SOURCE[0]}")"
+__base="$(basename ${__file} .sh)"
+__root="$(cd "$(dirname $(dirname $(dirname "${__dir}")))" && pwd)"
+
+# Set __usage and source main.sh
+read -r -d '' __usage <<-'EOF' || true # exits non-zero when EOF encountered
+  -1 --one         Do one thing. Default="ONE"
+                   More description.
+  -2 --two         Do two things.
+                   More description. Default="TWO"
+  -3 --three [arg] Do three things. Default="THREE"
+                   More description.
+  -4 --four  [arg] Do four things.
+                   More description. Default="FOUR"
+  -5 --five  [arg] Do five things. Default="FIVE"
+                   More description. Default="OOOPS"
+  -6 --six   [arg] Do six things.
+                   More description.
+EOF
+
+echo "ACCPTST:STDIO_REPLACE_DATETIMES"
+
+source "${__root}/main.sh"
+
+for argument in ${!arg_*}; do info "${argument}: ${!argument}"; done