diff -U2 -r /var/lib/copr-rpmbuild/results/i2pd-git/upstream-unpacked/Source0/i2pd-openssl/Makefile.linux /var/lib/copr-rpmbuild/results/i2pd-git/srpm-unpacked/i2pd-openssl.tar.gz-extract/i2pd-openssl/Makefile.linux
--- /var/lib/copr-rpmbuild/results/i2pd-git/upstream-unpacked/Source0/i2pd-openssl/Makefile.linux	2026-03-09 21:02:17.000000000 +0000
+++ /var/lib/copr-rpmbuild/results/i2pd-git/srpm-unpacked/i2pd-openssl.tar.gz-extract/i2pd-openssl/Makefile.linux	2026-03-09 20:48:46.000000000 +0000
@@ -10,11 +10,14 @@
 ## custom FDLAGS to work at build-time.
 
-# detect proper flag for c++20 support by compilers
+# detect proper flag for c++17 support by compilers
 CXXVER := $(shell $(CXX) -dumpversion)
 ifeq ($(shell expr match $(CXX) 'clang'),5)
-	NEEDED_CXXFLAGS += -std=c++20
-else ifeq ($(shell expr match ${CXXVER} "10]"),2) # gcc 10
 	NEEDED_CXXFLAGS += -std=c++17
-else ifeq ($(shell expr match ${CXXVER} "1[1-9]"),2) # gcc 11+
+else ifeq ($(shell expr match ${CXXVER} "[8-9]"),1) # gcc 8 - 9
+	NEEDED_CXXFLAGS += -std=c++17
+	LDLIBS = -lboost_system -lstdc++fs
+else ifeq ($(shell expr match ${CXXVER} "1[0-2]"),2) # gcc 10 - 12
+	NEEDED_CXXFLAGS += -std=c++17
+else ifeq ($(shell expr match ${CXXVER} "1[3-9]"),2) # gcc 13+
 	NEEDED_CXXFLAGS += -std=c++20
 else # not supported