diff --git a/src/app-utils/c-interface.scm b/src/app-utils/c-interface.scm
index 548e3bb5ae..10837a4c64 100644
--- a/src/app-utils/c-interface.scm
+++ b/src/app-utils/c-interface.scm
@@ -15,6 +15,7 @@
 ;; 51 Franklin Street, Fifth Floor    Fax:    +1-617-542-2652
 ;; Boston, MA  02110-1301,  USA       gnu@gnu.org
 
+(use-modules (ice-9 slib))
 (use-modules (ice-9 syncase))
 
 (define (gnc:error->string tag args)
diff --git a/src/business/business-reports/aging.scm b/src/business/business-reports/aging.scm
index 407cceceb8..499555bd1b 100644
--- a/src/business/business-reports/aging.scm
+++ b/src/business/business-reports/aging.scm
@@ -26,6 +26,7 @@
 
 (define-module (gnucash report aging))
 
+(use-modules (ice-9 slib))
 (use-modules (gnucash main))
 (use-modules (gnucash printf))
 (use-modules (gnucash gnc-module))
diff --git a/src/business/business-reports/easy-invoice.scm b/src/business/business-reports/easy-invoice.scm
index c507b9953e..18717fee5f 100644
--- a/src/business/business-reports/easy-invoice.scm
+++ b/src/business/business-reports/easy-invoice.scm
@@ -31,6 +31,7 @@
 (define-module (gnucash report easy-invoice))
 
 (use-modules (srfi srfi-1))
+(use-modules (ice-9 slib))
 (use-modules (gnucash printf))
 (use-modules (gnucash gnc-module))
 
diff --git a/src/business/business-reports/fancy-invoice.scm b/src/business/business-reports/fancy-invoice.scm
index d503112f3b..58c49c1192 100644
--- a/src/business/business-reports/fancy-invoice.scm
+++ b/src/business/business-reports/fancy-invoice.scm
@@ -49,6 +49,7 @@
 (define-module (gnucash report fancy-invoice))
 
 (use-modules (srfi srfi-1))
+(use-modules (ice-9 slib))
 (use-modules (gnucash printf))
 (use-modules (gnucash gnc-module))
 
diff --git a/src/business/business-reports/invoice.scm b/src/business/business-reports/invoice.scm
index c2b05cca2c..9780221100 100644
--- a/src/business/business-reports/invoice.scm
+++ b/src/business/business-reports/invoice.scm
@@ -25,6 +25,7 @@
 (define-module (gnucash report invoice))
 
 (use-modules (srfi srfi-1))
+(use-modules (ice-9 slib))
 (use-modules (gnucash printf))
 (use-modules (gnucash gnc-module))