diff --git a/share/completions/gcc.fish b/share/completions/gcc.fish
index 6311adad7..e28970325 100644
--- a/share/completions/gcc.fish
+++ b/share/completions/gcc.fish
@@ -463,7 +463,7 @@ complete -c gcc -o fno-show-column -d 'Do not print column numbers in diagnostic
 complete -c gcc -s A -d 'Make an assertion with the predicate predicate and answer answer'
 complete -c gcc -s A -d 'Cancel an assertion with the predicate predicate and answer answer' -x
 complete -c gcc -o predicate -d 'Cancel an assertion with the predicate predicate and answer answer' -x
-complete -c gcc -o dCHARS -d 'CHARS is a sequence of one or more of the following characters, and must not be preceded by a space'
+complete -c gcc -o d -d 'CHARS is a sequence of one or more of the following characters, and must not be preceded by a space' -x
 complete -c gcc -s P -d 'Inhibit generation of linemarkers in the output from the preprocessor'
 complete -c gcc -s C -d 'Do not discard comments'
 complete -c gcc -o CC -d 'Do not discard comments, including during macro expansion'
@@ -480,9 +480,7 @@ complete -c gcc -o Xassembler -d 'Pass option as an option to the assembler'
 complete -c gcc -s c -d 'Compile or assemble the source files, but do not link.'
 complete -c gcc -s S -d 'Stop after the stage of compilation proper; do not assemble'
 complete -c gcc -s E -d 'Stop after the preprocessing stage; do not run the compiler proper'
-complete -c gcc -o llibrary -d 'Search the library named library when linking'
-complete -c gcc -a '-l(path basename /usr/lib/lib*.so* | string match -r -g "^lib(.*?)\.so.*")'
-complete -c gcc -s l -d 'Search the library named library when linking'
+complete -c gcc -s l -d 'Search the library named library when linking' -xa '(path basename /usr/lib/lib*.so* | string match -r -g "^lib(.*?)\.so.*")'
 complete -c gcc -o ldl -d 'Search the dynamic loader library when linking'
 complete -c gcc -o lm -d 'Search the math library when linking'
 complete -c gcc -o lz -d 'Search the zlib library when linking'
@@ -501,8 +499,8 @@ complete -c gcc -o static-libgcc -d 'Force static libgcc'
 complete -c gcc -o symbolic -d 'Bind references to global symbols when building a shared object'
 complete -c gcc -o Xlinker -d 'Pass option as an option to the linker'
 complete -c gcc -s u -d 'Pretend the symbol symbol is undefined, to force linking of library modules to define it'
-complete -c gcc -o Idir -d 'Add dir to the head of the list of directories to be searched for header files'
-complete -c gcc -o iquotedir -d 'Add dir to the head of the list of directories to be searched for header files only for the case of #include "file"'
+complete -c gcc -o I -d 'Add header search directory' -xa '(__fish_complete_directories)'
+complete -c gcc -o iquote -d 'Add header search directory for #include "file"' -xa '(__fish_complete_directories)'
 complete -c gcc -o L -d 'Add dir to the list of directories to be searched for -l'
 complete -c gcc -o B -d 'Specifies where to find the executables, libraries, include files, and data files of the compiler itself'
 complete -c gcc -o specs -r -d 'Process file after the compiler reads in the standard specs file'